Haswell Overclocking Thread

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Set Uncore (AKA Ring Bus) to core ratio to manual. Set it to stock multiplier manually. With ring bus running on stock and locked at stock for now, no need to fiddle with ring bus voltage. That goes to auto. Some motherboards MAY increase Vring to unsafe levels if you didn't manually set ring bus to stock because the motherboard will try to auto-overclock the ring bus if left on auto. Avoid future headaches by following step 1. If you have a Gigabyte motherboard, set uncore to x33. Reason stated in the next bolded section. Set any XMP profile OFF for ram. If your ram is above 1600, set it to 1600, no higher while we're testing overclocks. Heck, if your ram is XMP'ed for 1600, lower it to non XMP. Doesn't hurt. Start ramping up the core multiplier and voltage until you think you've found your sweet spot. You might need to increase input voltage from the motherboard-set setting once you hit higher voltages. More on that later. Do stress test and if you pass, go to step 4. NOTE: Yes, you up the core multiplier by 1 each time. You can probably get away with starting at 4ghz though. Because the core clock is 100, 100 x 40 = 4000mhz or 4ghz. Now we fiddle with ram, higher ring bus/ring bus voltage in effort to get marginally better performance. Stress test. Do not raise ring bus or ram if it means lowering core clock for stability. If you are hardcore or have a lot of time on your hands, you can try adding clockstrap to the mix but I'd stay away from it unless you're super duper picky. Nobody has reported very good results with this but you're welcome to experiment. Set Cstates to ON to C7. If you really care about lowering idle voltage, hit ctrl+f and search for "Power Saving Info". Have a glass of iced tea.

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Which test are you running on what setting? Double check with the chart down below. For example, Aida64 full suite is NOT the same as Aida64 FPU test only. IBT is hotter than Prime 27.9 but not hotter than Prime 28.3 on small. Prime 27.9 is cooler than Prime 28.3. Ensure you are not getting Vcore spikes due to adaptive voltage while stressing on synthetics. If your temp from one core is 10C+ hotter or cooler than some other core in a load that loads all CPU to 100%, it might be a thermal paste application error. Pea method, folks. 10C degree difference and lower is NORMAL on stress tests. Does your cooler just suck? Are you trying to apply Sandy Bridge voltages onto Haswell? It is hypothesized that some temperature variance between CPUs is normal because the way the gunk inside the CPU under the IHS is applied is spotty, better in some and worse than others. While this is NOT backed up by actual scientific testing, it makes sense and accounts for the temperature variance. Hyperthreading makes the CPU hotter. This means 4770k might run hotter than 4670k.

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Did you read the entire guide? No, seriously. Did you? Did you ask a question in this thread? Listing more info than is needed is typically better than listing too little. What is your Core and uncore multiplier, their respective voltages, input voltage, ram speed and timings, CPU, base block, and used stress test? What is your Bsod code if you have one? It crashed? How did it crash? What temperatures were you getting? Did you remember that higher Vcore means a higher Vrin is required to maintain stability? Did you set uncore to stock? Is the voltage for that uncore ridiculously low? Did you overclock your ram or GPU? Did you try to run Prime95 for 1,000,000 hours?

AVERAGE OC 45.39 MEDIAN OC 45.00 AVERAGE VID 1.29 MEDIAN VID 1.28

Welcome to the Haswell Overclocking Guide. In here I will do my best to provide information regarding Haswell overclocking. This is a guide driven by experiments, tests, and feedback accumulated from 15000+ replies.(Click to show)Why use this guide?I get data from tests instead of taking claims from others on face value. I spend a long time testing each setting and charting the data to make sure my data is right. I have a long chart of OC results from OCN members with all of their settings noted. Average OC, etc, are derived from those values. I still update this guide and this guide is built and updated upon thousands upon thousands of replies.What is overclocking?Simply put, you up the performance of the CPU, typically by increasing its core clock speed. With 4670k/4770k we do so by upping the multiplier. So a x44 multiplier with 100 base clock is 44 x 100 or 4400 mhz or 4.4 ghz.I am not responsible if your CPU dies. Just use common sense, watch the temperatures before you dash off to stress test for hours on end, read the entire guide before doing random changes, etc. There has been no confirmed Haswell CPU deaths I have seen due to sticking to my guide with my parameters for what is safe.What is Haswell?Haswell is the forth and latest-gen cpu line out for consumers. Of all the ones released the two of most interest are the 4670k and the 4770k (~$220, $330 respectively). These are the two unlocked versions of Intel's line of CPUs. This means we can adjust the core multiplier for overclocking later. It has IPC improvements over Ivy Bridge, meaning a 3.5ghz Haswell will typically beat a 3.5ghz Ivy Bridge. take that into consideration if you get a lower overclock. Its integrated graphics are of no concern for the PC enthusiast as you will end up buying a discrete graphics solution. Of course, the 4770k is an i7 with hyperthreading and the i5 does not have that. There is no shrink this time; the manufacturing process stays at 22nm. This is the tock in the tick tock model from Intel.What about turbo?The 4670k turbos to 3.6ghz if all cores are under use. This is the default 'overclock'. It goes higher if only a few cores are used.What is this USB 3 error I heard?There were some issues with sleep mode and USB 3 slots on some motherboards at the very start. The problem was caught and as far as I can tell, no consumers have been complaining about USB 3 issues and the vendors assure us that the issue has been fixed already.What socket is this chip?This chip is a socket 1150 chip. You will not be able to use the same motherboard from any generation ago. You will be able to use the same cooler if it worked with the 1155, however. This includes the popular Coolermaster Hyper 212 Evo, Noctua D14, etc.Why the motherboard change?This is due to power changes in the CPU. Some parts relating to CPU power control have been moved from the motherboard to the CPU. This allows for more advanced power states for the CPU. Mean note that while CPU power draw as a whole did not decrease at peak by that much, that some elements of the motherboard have been moved to the CPU causing the overall power consumption of the system to decrease as a whole.What about chipsets?The chipset of concern is the new z87 chipset. It allows for more 6gb Sata connections... for a total of 6. Up to 6 USB 3.0 ports will be available with native support. Typically you will find PCI 3.0 slots. Please note that a x8 PCIE 3.0 is equivalent to a x16 PCIE 2.0 slot. Ram is typically supported up to 3000mhz DDR3. In addition to all of these benefits, the onboard audio has been updated to the new ALC 1150 standard. Although the specifications are superior, please note it's the total integration of the technology that dictates the end sound quality.Any info on batches?There are the Malaysian batches and the Costa Rica batches. I've listed all the results from other people down in the graph later in this thread. I noticed no major difference between batches however I have not heard of a seriously bad Costa Rica chip yet. It may be due to the fact those are still rare. It's hard to figure out how well a CPU will overclock if you don't overclock it, but one very dodgy way of doing it is to check stock VID.What about delidding?Unfortunately, Haswell comes with problems of its own that would be fixed by a proper delidding. Please note that delidding may make your CPU harder to sell again and it may be dangerous if it goes wrong. The glue used to hold everything together left some room under the IHS or integrated heat spreader. You can use the razor blade method but I recommend the vice method as it is much safer. Please watch videos on it and ask around for more info before attempting. If you do something stupid, you've just broken your CPU. It doesn't happen all that often, but do be careful. I recommend going over to the delidding page for specifics but the very quick rundown is to clamp the CPU onto a vice, and hit it with a wooden block so the top metal part of the CPU pops off. Remove the gunk, add your choice of applicant... Coollaboratory is well regarded for this task. Thin layer. You can expect a good 10C decrease in temps, maybe more. Go to http://www.overclock.net/t/1313179/official-delidded-club for a nice guide on delidding.My recommendation is to not go into Haswell with delidding as your first goal. Only delid if you are thermally limited and you feel being able to crank voltage up a bit and thus generating more heat is vital to getting the next multiplier. You may find out going to the next multiplier is unstable no matter what voltage. First thing to do is to drop to x264 stress test and see if the temps are OK there. Delidding only makes sense when your overclock is being severely impeded by temperature AND you have voltage headroom. Often, this thermal issue can be bypassed by using a less hot stress test. I got approximately the same temperatures from 1.2v @ Linpack vs 1.5v @ Chess. Also, delidding won't help if your voltage headroom is very small. Delidding is to decrease temperatures to allow for higher voltages. If you can't push higher voltages despite being cooler out of fear of degradation, then delidding is mostly pointless as well.Is there any insurance for my CPU?Intel has a protection plan you can buy with your CPU for $25. It is designed to cover CPU death due to overclocking. It is not designed to cover delid-deaths but one guy said he managed to exchange his dead Haswell for another one even though it was delidded. Bear in mind that may just be due to the one kind Intel service rep that day.(Click to show)Is your heatsink/cooling solution up to par with what you wish to attempt? Expect hot temperatures ahead. Overclocking isn't horrible, but the heat will be biting. Anything under 80C is absolutely OK for 24/7 running even for the paranoid. 90C or higher is only acceptable during a stress test. Please avoid 100C, that is dangerous and the CPU will attempt to throttle. It's bad practice to have the CPU so hot, it throttles.Stock -> Coolermaster Hyper 212 Evo -> Noctua D14/Thermalright Silver Arrow -> x60 Kraken -> Custom LoopFirst, a little bit of a heads up on Cstates. Whereas normally my computer would hammer my CPU with 1.42v of juice, it will now sip, say, 0.3v doing daily activities that I do but scale up when more power is required. This is very good for the longevity of your CPU as well as for power savings. You need to adjust the option in your motherboard BIOS. Enable C states. The higher the C state, the deeper the power savings. I set it to C7. No, no performance penalty/stability has been noted with this setting. Some people reported their power delivery being higher than estimated on idle because their power options in Windows is set to performance, not balanced. It does not affect me personally. To check if Cstates are working, close all major programs. Open HWMonitor or HWInfo and check the Vcore, not the CPUVid. The Vcore should jump around and increase as load increases. (BTW: The "watt" reading from HWinfo is sketchy at best. It's not that useful and the accuracy is questionable.) Don't forget, some versions of CPUZ are really sketchy for measuring Vcore.What about Adaptive? I'll talk about this later in the guide but right now I recommend setting voltage mode to Override. Gigabyte boards don't even have adaptive options.Most of the time people who say they can't find it simply didn't look in the right place but sometimes the sensor is simply missing. It may even go under another name but typically as a voltage reading that is close to the area where Vcore reading would be. If you have Cstates at 7, and a reading is jumping around and hits your set VID when under load, then that is your Vcore reading. What is VID and what is Vcore? I'll talk about it later.stress synthetics with adaptiveIt can force the motherboard to give the CPU more volts than you set it to under very heavy loads. This primarily happens with synthetic programs. Stressing with adaptive may overwhelm your cooling solution and cause sad things to happen. With override mode while running normal programs, you MAY still cause the CPU to get more voltage than you set it to, but the difference is down to say, 0.03v max. That isn't too bad but that is still significant, so be aware. The size of this small bump is basically the same from CPU to CPU. Some think this is due to a sensor inaccuracy. Either way, this small bump is normal.This is still a new launch and bugs and updates are expected! Update your stress test and your monitoring programs! Note: New stress tests might be more intensive.(Click to show)First and foremost: Expect overclocking results to differ. We should all know by now that not every chip is created equal. With Haswell, this is more true than ever. I'm serious. Your motherboard isn't nearly as large of a factor as it used to be. It's almost all up to your luck with your CPU now. Expect a very wide variance in end results. It's a silicon lottery, folks.Override voltage mode the same thing as manual voltage mode. For stress testing neither uncore nor core should be at adaptive mode.If you simply raise the multiplier on the core and change the voltage, you'll probably run into a bad overclock because the overclocked ring bus will hinder the core overclock. And they say it but it's true: Core is king.You'd generally rather have stock ring bus if that means getting 100mhz faster core clock. Same for ram of course... it's a tall order to hit DDR3 3000 with higher overclocks.I've posted benchmarks under this section somewhere, which shows graphs proving ring bus settings to be of little consequence in benchmarks and applications. Keep in mind if you are adamant in overclocking the ring bus you also need to provide extra voltage to it. Your core clock should always be equal to or higher than your ring bus.If you are using a high Vcore for your overclock, typically for the higher multipliers, input voltage may also be important. I'm talking about 1.30v and up. Info listed later in the guide.Gigabyte motherboards have been noted to automatically ramp up uncore to x40 when you manually set it to stock. So just set it to x33. You can also set it to x34 if you have a 4770k, or x35 if you have a 4670k, it doesn't matter. (Yes, stock core and uncore frequencies are both 3.4 for 4670k, 3.5ghz for 4770k.If you have an Asus motherboard, there has been some chatter about bios versions. Some people say that version 804 of the bios is best for overclocking. The point is, different versions of the bios may positively or negatively affect your max OC. Please note that none of this has been personally tested by me because I do not own an Asus motherboard.You up the vcore slowly. You don't go from 1.1 to 1.2 to 1.3 to 1.4v just like that. Maybe you can start at 1.2, 1.25v but that really varies on the stress testing method. The problem with going straight to a higher voltage is, you may overvolt and use a setting that is less than optimal for stability (not proven) or temperature (obviously proven). Say you start OCing by going to x45 and using a whopping 1.45v straight up and it works. If you don't back down that voltage and you leave all that unnessary voltage about, you will not only cause more heat than you need to, you will decrease the longevity of the CPU for no good reason. At minimum I suggest going from 1.2 to 1.25 to 1.3 to 1.35 to 1.4. Any larger jump I think is completely useless for attaining a good, fine voltage.When you plug in a higher voltage for the first time or use a stress test for a first time, eyeball the temperatures. You can go from 70C in x264 to 100C in Linpack quite easily and if you run off to make a sandwich, you risk hurting the CPU when you could've watched the temps for the first 10 seconds of the stress test and avoid this.If x44 is stable, don't jump to x46, and then say it's not stable. And for the love of god, don't waste your time telling us x47 or x48 is unstable.In a scientific study, you have a control group and an experimental group. Basically, you see the effect a change in a variable has on something. You do not change 50 things and then draw a conclusion that all 50 things contributed or caused the result. You change one variable at a time. If I overclock core and uncore at the same time and I crash, how will I know which caused the crash? I won't. There's nothing wrong with overclocking the uncore, but it's secondary because the performance change is less than a core overclock. That makes the core overclock the most important. So do the core overclock first until it's stable. That way, if you ever crash after overclocking uncore, you know for sure it's the uncore settings causing instability. This is yet another reason to follow this guide in this order.In a perfect world we'd all be running 1:1 cache ratio, but we'd also be running 500 ghz overclocks and sipping iced tea on clouds. We don't live in that world. If you got a cherry picked unit, fine, you can hit 1:1. For the rest of us, you cannot, pure and simple. Say the highest core overclock you can get is 4.6ghz. If you try to bring your uncore also to 4.6ghz, very likely you've either 1) Crashed your system because the uncore OC makes the core OC unstable 2) Crashed because you lack sufficient Vring 3) Applied unsafe Vring. You can't get past the first issue. You'd rather have 4.6ghz core and stock uncore (3.4ghz is stock core and uncore for 4670k, 3.5ghz for 4770k) than 4.5 core and 4.5 uncore. So what the heck is this 1:1 Cache Ratio nonsense?It's the idea that your ring bus helps your performance up until it is the same speed as your processor. But you should know by now that ring bus helps performance... by a super small margin. The amount is negligible. It's basically saying, if your ring bus is higher than your core speed, that extra ring bus isn't doing anything supposidly. But the entire point is useless as pretty much nobody can hit 1:1 in the first place, let alone get above 1:1. Let me make this crystal clear: 1:1 doesn't make your CPU magically faster. You don't get an extra boost for doing 1:1. It's the same boost from 1:0.9 to 1:0.95 as 1:0.95 to 1:1. The amount of performance gain from uncore is roughly the same no matter how close your uncore is to your core. All that jabber about "keeping uncore 200-300mhz below core" is simply misleading. There is no such bottleneck that occurs if it's lower which those people seem to imply, and I have hardcore benchmark after benchmark to back up my statement. You overclock core with uncore set to stock so it doesn't lower your max core overclock. Then you overclock uncore without ever lowering core to get a higher uncore. If it happens to be 200-300 mhz under your core, awesome. If not or you don't want to push an unsafe Vring, that's fine too. Overclocking Haswell is complicated as is, last thing we need is to mislead and confuse people with 1:1 ratios.You will pretty much always be fine at 1.2v for core voltage provided you're not stressing on synthetics. Synthetics are things like Linpack, Prime95, Aida64. They are just that, synthetic tests, as are not actual real-world loads. Non-synthetic stress tests would be like chess or encoding a video with CPU only.If you do want to stress I recommend Noctua D14 as a starting cooler. What happens if you have a 212 Evo from Coolermaster and you want better cooling? You now are stuck with a lower-end cooler.At 1.35v or higher, x264 is the recommended stress testing method. Some question the validity of an overnight x264 loop for stability but so far no evidence has shown it is insufficient. Otherwise only high end closed loop or a custom loop should play at this setting. Haswell temperatures are very reliant on voltages, not frequency. Note that while I said, for example, that 1.35v requires a high end closed loop solution or better for Linpack stressing, that does not mean that's required for gaming/any other non-synthetic application. Only you can decide what sort of stability is acceptable to you.If you do a multiplier assuming it's stable and later get a Bsod or Bsod after later moving on to a higher multiplier, you might be tempted to blame the CPU or degradation when in fact it was your own insufficient testing in the first place.Nowdid I list my recommendations about voltages this way? What matters in the end are two things when it comes to voltage safety: A) You do not hit above 95C under whatever you wish to stress and B) You do not exceed 1.45-1.5v no matter what. The thing is, most people run into the first problem long before they hit the second, because by 1.35v if you want to run Linpack, you're already getting dangerous temperatures on air. If you are using a custom loop with a delid though, the second problem might hit you first. Personally I am running 1.42v at 4.6ghz on D14 and the only reason why I can do so is because I'm not stressing with Prime or Linpack. However if my settings are stable then I can squeeze in that extra 100mhz because the max real-world loads will not anywhere near Linpack. But let me repeat this implied point: Simply saying "this voltage is too much" is typically insufficient.Quick note on auto-overclocking: It will not be as efficient as manual. Do it manually. I wrote a guide. Use it. If you have MSI motherboard, OCGene will block manual overclocking. You need to click on the OCGenie button in the BIOS to stop that from happening. Lower end MSI boards may be voltage locked above a set amount, say 1.3v! Beware!The naming used differs between motherboard manufacturers. Keep in mind that Uncore is the same as Ring Bus, and is sometimes known as 'cache ratio'. Some boards have 'minimum' and 'maximum' cache ratio. Just set them to the same. Obviously, 'cache voltage' is 'ring bus voltage' or 'uncore voltage'. I would recommend that you stay under 1.3v for uncore voltage. Ring bus takes less voltage, don't just replicate it as if it were core clock. You are going to need to raise ring bus voltage if you plan on overclocking the ring bus significantly. If your ring bus is manually set to the default value, meaning it's not overclocked for sure, leave it at auto is typically fine, but you can set the uncore to 34 or 35 (doesn't matter) manually and then set uncore voltage to 1.2 so there is no way the motherboard can accidently overclock your uncore or use a super low uncore voltage by default. Try not to exceed 1.35v. I try to keep it at 1.3v or under personally. If you do not set ring bus to stock multiplier manually, some motherboards will try to overclock it on its own, which might not only crash your system, it could also damage your CPU because the dumb motherboard is setting an unsafe voltage!Is 1.3v+ safe? Nobody knows and nobody needs to know. Uncore affects performance so little, and as you increase multipliers, the extra amount of voltage required for that extra multiplier increases over and over. If you're hardcore enough to care about the small difference you might be able to net in 1.3v+ uncore voltage, breaking a CPU or two won't matter.The VRIN can be thought of as the entire amount of voltage drawn by the CPU and all of its components.When your Vcore is really going up, at least 1.30 probably 1.35v or above, you may need to change other settings. For one, keep your Vccin or total CPU voltage to 0.5v above Vcore. You can try 1.9 or 2.0v. 2.2 is uncharted territory, but for my personal overclock, a Vcore of 1.42 required Vccin of 2.15v for stability. Vccin is also known as Vrin. In Asus ROG boards, try tweaking the "eventual input voltage" instead. No benefits have been recorded by tweaking the "initial input voltage" setting.I recommend changing input voltage in 0.05v increments. Any less you need a zen-like patience to test everything. I recommend max 0.1v increment if you are lazy. Do not do the same with Vcore or other types of voltages obviously. The reason why input voltage becomes a larger factor at higher Vcore is because input voltage is typically automatically managed by the motherboard's own software. But when the Vcore goes high up, the motherboard almost never compensates the input voltage well enough to ensure stability. Depending on how good your motherboard is at making sure the CPU has enough input voltage for the Vcore, you may have to tweak the input voltage before you even hit 1.3v Vcore.For my case, I was trying to get x46 core multiplier and could not stabilize. Odd, considering x45 was rock solid @ 1.35v. I scaled up voltage from 1.35 to 1.4, 1.42, 1.47, 1.5, 1.512v, without being any more stable as voltage went up. The key was a higher Vcore, AND a higher input voltage. I demonstrated this by testing stability at 1.42v with various input voltage. I tested by running x264 until Bsod 5 times per setting, keeping track of averages. From 1.85 to 1.95 to 2.05 to 2.15, I could see demonstrable improvement in stability, with a higher maximum, minimum, and average time until Bsod. So what is this saying? Often times we are just tempted to test the Vcore and if it doesn't work, just get a higher Vcore, and higher, until we use ridiculous voltage and still crash, where we then put our hands in the air and give up.Also keep in mind that the amount of Vrin you need for a specific Vcore varies from CPU to CPU.For Haswell, this is a setting for Vrin, NOT Vcore.Please note I can only test LLC for MSI G45 Gaming Board. For this mobo, the setting is under the "DigitAll Power" section. Also note that LLC is for Vrin, NOT Vcore, Load tested with Prime95 28.3 with HWinfo. The Vrin as set by BIOS is 2.15v.12% LLC:IDLE: 2.176vLOAD: 2.112v100% LLC:IDLE: 2.176vLOAD: 2.16vThis means that upping that LLC can potentially help you when your Vrin is the offender.Also, you may need to alter the voltages for SA, IO Analog, IO digital as well. Try adding 0.1v to them.Please note: It is unclear at this point what voltages are dangerous. Be careful with these voltages. JJ from Asus said these voltages help stabilize a higher Dram divider but I got 9c errors at as low as 1600 DDR3 while managing a stable 2133 OC without touching these.There is a difference between CPU VID and CPU Vcore when I mention both of them together. I repeat: Only when I am talking about VID and Vcore in the same sentence does my definition of Vcore change.Normally when I say Vcore I mean what you think I mean. But when I mention VID vs Vcore, VID is the amount of core voltage you set in the BIOS yourself. You should know it, you're the one that set the voltage in there. The Vcore is the number measured by Hwinfo or HWmonitor on your CPU when it is under max load.What does this mean? Your Vcore could be above your VID. If you set 1.3v in the BIOS that's 1.3v VID. If you are also under adaptive voltage and you're running Prime95, your Vcore could be a whopping 1.5v, way above your set 1.3v.Finally please note, there are multiple reports of people having a higher Vcore than VID even under non-synthetic loads but the extra voltage is relatively small. Just be careful and monitor voltages closely. As your VID increases the extra voltage drawn in from a regular non-synthetic load increases.When you Bsod, it shows a code outlining what happened. However, with Haswell I've noticed that the code itself isn't a perfect tool to diagnosing what exactly is wrong with your OC, just that something is actually wrong with your OC and it's CPU related. The codes are 101, 124, 9c. When you get those, you know your CPU OC isn't perfectly stable. If you're getting some oddball code like 116, 3B, etc, then something else is causing the computer to crash. Yes, you can make Bsod screens stay up until you manually restart. A google search should net the answer. In Windows 7 at least, after a Bsod, Windows shows what the Bsod code was. Windows 8 also has Bsod "codes", like Error Time Watchdog, etc. You can check your Bsod code sometimes even though you didn't actually see the blue screen. Sometimes on Windows 7, upon starting up the computer again, it'll say 'last time something happened' and show you the Bsod code in the description. You can also try Bluescreen Viewer.Everything is off of past experience and estimations. Nobody can tell you for sure because to do that we need to destroy multiple CPUs to tell. Degradation also needs to be checked and that would take a year at least of testing and multiple CPUs set at various different voltage settings. In other words, real testing is impossible.The sad part about Haswell is that motherboard vendors do whatever they want. Uncore can be called ring bus or cache ratio or whatever. It's similar with power saving but worse. For MSI G45 Gaming motherboard, adaptive is ABSOLUTELY USELESS as a setting. It does absolutely nothing for voltage under load or on idle. All it does is give you the risk of borking your CPU if you run it with Prime. I've testing this through and through on this motherboard because the result was so counter-intuitive. For MSI G45 mobos, to get power saving you need to have C states set to 7 for maximum power saving on idle. If you want multiplier drop on idle, you need to enable EIST in the BIOS. Having C7 and adaptive vs C7 and override/manual voltage mode made zero difference in idle voltage. There are conflicting reports for other motherboards on what is required for voltage drop on idle. I do not have the money to buy multiple motherboards and do a battery of tests of each motherboard. So I just say, figure it out yourself. The relevant settings are adaptive vs manual voltage, C states, and EIST. No identifiable temperature drop or performance drop was noted by using Cstates or EIST from my tests. If you have a Gigabyte motherboard, adaptive isn't required for voltage drop because... well, you don't have that option to begin with. Just Cstates for you.A little bit more on EIST: Dropping multipliers on idle has no measurable difference on idle power draw. It does not increase the lifespan of your CPU because clock speed doesn't kill CPUs, voltage does. Clock speed doesn't draw more power, voltage does. Lower clock speed on idle is irrelevant for temperatures as even 1.5v Vcore on idle is dead cool. For MSI G45, the EIST option is "multiplier mode", which must be set to variable instead of fixed. In Windows, your power settings must be set to balanced. You need to restart for the settings to take effect, and once you boot into desktop you must wait a minute or two for the settings to kick in and the multiplier to drop on idle. I literally mean a minute or two, as in 60-120 seconds.(Click to show)Credits to Maxforces for the second part of the benchmarks. From my personal benchmarks, I found the drop of 0.7ghz for the ring bus to be an equal performance hit of 0.05ghz decrease in core clock and this difference shows in a very CPU reliant benchmark like chess.And here are the most recent tests for uncore that I have done:The 4.2 vs 3.4 is the uncore setting. The core multiplier for this test was x45.Testing methodoloy in this test is much more well documented by me.Chess: Houdini 3, 9mb hash, starting position, 5 minutes.BF3 Multiplayer: 64 player server in a closed map (Canals). Regular gameplay for entire round.BF3 Campaign: Second misson, following scripted NPC movement.Enemy Territory: 30 vs 30, Fueldump.Runescape: GE, World 3. Capturing FPS while stationary. Max detail, non HTML5. x4 AA Bloom enabled. (It seems to use CPU to do AA)Oblivion 1: Walk out in the wild, through Oblivion gate, to town gate.Oblivion 2: NPC combat in Imperial City. Several guards/NPC vs Umbra. Spawn 50 player copies and begin combat once Umbra dies.These were done on tests, as you can see, that vary from CPU benchmarks to CPU reliant games.Maxforces Says:Test setupResultsbut if you play 3dmark you will gain some pionts(Click to show)This kind of thinking might had merit in previous generation CPUs, but in Haswell at least, it is a load of bollocks. As you can see from my chart below, the range of temperatures vary wildy from test to test. We are talking about a 45C difference in temperatures. If I had stuck to Linpack or go home, I would be down from 4.6ghz to 4.1ghz. (This is backed up by testing.) This is insane. Linpack is so ridiculously hot, so completely out there, it's not worth counting. The mentality of passing all tests for the sake of stability is more irrational than you might presume at first glance. That kind of mentality means passing whatever test people happen to be able to make. If nobody made Linpack, then you would think your CPU is stable. If somebody made Linpack 2.0 that makes Linpack 1.0 look like child's play, then you might as well never overclock, because Linpack is throttling a few people at STOCK. Indeed, Linpack uses AVX2 which is a new instruction set, but so does x264, and that is one of the coldest benchmarks. Stressing AVX2 set doesn't nessesarily mean high temps and failing Linpack doesn't mean AVX2 instability. And how will you know when to stop stress testing under the original ideology? You can only estimate. Computers are built for using, not for stress testing. If you're running Linpack, and you're under the opinion that you must pass all possible tests, you need to update the math logic for Linpack and run it at MAX setting. That means using up all of your available ram for the largest problem size.Run 2-3 different types of stressing programs, and then use your computer normally. If you crash, then it's not stable. What's stable for you might not be stable enough for me. Some people need 100% reliability because of their jobs. Some people can handle a Bsod once a week. NO, saying that you want to pass Linpack 'just in case you use your CPU to extreme limits' is complete hooey. Prime95 is already ridiculous. Linpack is ridiculous on top of ridiculous on top of unicorn blood powered by the core of the sun, worshipped by space aliens. What if there comes out a new normal application that uses as much CPU power as Linpack? Well, there is no hint of that happening, so this is just a 'what if'. Well, what if there comes out a new application that throttles you at stock? Then let's all downclock our CPUs! If you insist on passing every test just because, fine, just don't expect any half-decent overclock. If I hit 95C+ easily at 1.2v with D14, there is no way anybody can hit 1.25v+ with Linpack set to max even after delid and x60 Kraken. And guess what, the average voltage setting for the OC results chart is 1.3v, so what does this tell you? You'll be lucky to stay on 1.25v after delid and liquid cooling and having a stable setting because between Prime 28.3, which discovers stability issues like a god and Linpack at max which raises temps like a god, you will be severely hampered by the combination of both tests.Don't give me that 'If you crash on anything, you're unstable, period' crap. Anything is decided by whatever program people decided to make. And if your definition of the word stable means not crashing in anything, ever, then I don't care about what you call stability. You will never know if something is stable by your own criteria because if you pass Prime for 500 hours, what's to say the 501th hour will be stable? That's right, you stop at some arbitrary time. I care about the computer not crashing often enough to annoy me. And that could be once a week, once a month, once a year, never, every 5 seconds. But as long as I'm fine with it, that's all that matters because it's MY CPU.If you're ever Bsoding 'too much', all you have to do, if you are in the heat of the moment, is to lower the multiplier by one and BOOM, rock solid stability.---While I was testing, the only stress test that Bsoded me was beta Prime.Refer to the temperature chart! Different versions of the same test will have different temperatures. Most notably is Linpack (some versions don't have AVX2) and Prime (28.3 is considered hotter). Also note in Aida that the setting you pick changes your resulting temperature. XTU Bench is hotter than XTU Stress. XTU Bench temperature increases as ram speed increases. Expect up to a 10% temperature variance. Don't forget, the settings I ran for the chart is listed in the Excel picture just above.You will not hit those temperatures under normal operation. If you hit 95C you might be fine outside of stress testing. It's very unlikely your games will seriously stress your CPU across multiple cores. The temperatures of x264 and chess tell you what temps you will see as a worst case scenario realistically.I highly recommend trying x264 encoding test if you are looking for a stressful nonsynthetic stress test. Nonsynthetic meaning temps will not be very high, being only a notch higher than normal 100% CPU load. Voltage will not increase dramatically like in Prime95 if you are using adaptive. But it'll still be very stressful, often causing crashes in an hour at most. For a peace of mind I recommend running x264 looped all night as you sleep once, and if it passes, it's stable. We have managed to produce a x264 version modified for stressing purposes instead of benchmarking purposes.Angelotti made a nice post with his tweaked and optimized version of x264. It is a little more stressful than standard x264 and has a few small improvements over the original x264. (This version has the Loop.exe built into the application itself; no fiddling with different exes.) This is the recommended version of x264 to use by default.Version 2.069/15/2015For those who want the original x264 for some reason, below is a link. It also includes an early version of the loop functionality.If you feel the need to use a hotter test that is your right but know that your overclock may be hampered by that choice. You could forego delidding in many cases simply by switching to x264. The default prescription for a stable CPU is a pass of overnight x264. Overnight means you set it to run when you start sleeping and if you wake up to a stable computer, you're good to go. That's a good idea because then x264 will not lag your computer while you're using it and you can easily go 8-12 hours without using the computer as you're asleep during that time.One test easier to pass is chess. I recommend using Arena GUI and Stockfish engine. Both are free. This is the easiest test to pass out of all of my suggestions.For some people, being unstable causes Prime95 to stop. This can come in the form of Prime95 outright crashing and closing entirely, or having a core or three simply stop working with an error noted. This means your overclock failed the test.Prime Beta (version 28.5): ftp://mersenne.org/gimps/p95v285.win64.zip Prime 27.9: ftp://mersenne.org/gimps/p95v279.win64.zip We recommend using HWinfo. HWInfo is the best if you want all the info in one place and you want tons of info. To measure and check your C-state settings you can only use HWMonitor or HWInfo. For me, the VCore is under my motherboard section, which may be confusing. It should be changing a lot. You need to use the latest version of the software! First check to see you have the latest version!I do not recommend using CPUZ. It has always been sketchy with the Vcore reading but some people are saying some versions are fixed. I'd rather use HWinfo and get all of my temps, voltages, etc in one place with VID and Vcore and Uncore all shown without glitches.Can't find VCCIN/Vrin on HWinfo? On Asus motherboards, try looking for VCOREREFIN.This game is known for being easily unstable under an overclock. Some people consider this a better test of stability than even Linpack! For Battlefield 4, be careful because crashes may be due to immature drivers for GPU or software issues!...Is currently still unstable as a game. So in terms of stability testing, it's of limited use. But if you BSod, well, that's still probably CPU overclock, not a crashy game. If the game just crashes, blame the game.Right, another unsubstantiated rumor floating around. No software is ever certified with a CPU. There isn't a committee that goes around with official badges handing out official certification after a 10 step process, ok? There have been zero proven reports of CPU death due to Prime95. You can say, better safe than sorry, in which I reply with, don't even overclock then! Nothing is absolute, but the data has come in and it shows the scare being unsubstantiated. Look at the chart, there are piles of people who stress with Prime95. Half of the misconceptions stirred from a claim that Prime raised voltages way above what is normal. YES, if you run it on adaptive. But the same thing happens for every other synthetic, Prime isn't special in any way. It just so happens that Prime is often the first stress test people run, and if they don't know about adaptive stressing, they will freak out at the voltages before they know the full picture.No significant or easily measurable increase in temps were present. The temperatures were within margin of error. Tested with Prime95 28.3 with HWinfo.Test settings:Default Setting:43/341.25/1.181.9v VrinTesting Uncore increase in temps:43/311.25/1.281.9v VrinTesting Uncore + Input Voltage:43/341.25/1.282.15vHaswell is still a new launch. That means programs associated with it will constantly get updates. Older versions of Prime are easier to pass than newer ones. Many programs have glitches. There are idiosyncrasies. The only way to iron out what's what is with your cooperation, and lots of communication.If you want to find out when your computer Bsoded for whatever reason, you can look at Windows/Minidump. It is time stamped.You can find out how stable your setting is by running a stress test and seeing how long it takes to crash. I tested what VCCIN is optimal by running x264 runs, 1.85, 1.95, 2.05v, 2.15v VCCIN and I recorded how long it took to crash after five tests. This is how I figured out I needed 2.15v VCCIN.(Click to show)4670k (without Hyperthreading), 4770k (with Hyperthreading).Typically 100. Multiplied with the core multiplier to get core speed or with the uncore multiplier to get uncore speed, etc. Screwing with this can screw with multiple components.The primary speed setting you change to change the CPU speed. x34 or x35 is typically the default. 100 base clock x 34 = 3400 mhz or 3.4 ghz.The voltage for core. Higher multipliers require higher core. aka Vcore.The secondary speed setting. Always of secondary important to the core multiplier.The voltage for uncore.The all-around voltage sucked in by the CPU for all the components. The higher the Vcore, the higher this should be.This is typically best attempted when you are trying to hit that last multiplier and you're unsure what the instability is from. Run x264 multiple times (I did 5). Each time the computer Bsods, that count as 1 run. Time how long it takes to Bsod. Then change one setting. Note any change in average time until Bsod. This is how you figure out whether a setting is increasing, decreasing, or not affecting stability without relying on personal feelings but hard data. Specifically, this will tell you if you need higher Vrin or Vcore or both.The reason why this test is effective is because it pinpoints the effect of a setting. Does increasing Vcore change stability? Yes or no? It can tell you the answer without you having the pass all of the runs. Just having a noticeable increase in average time until bsod demonstrates an increase in stability. Or maybe it's input voltage that's problematic. You can test that too. Just change the input voltage and see if the stability changes. For this test I would change input voltage in 0.1v increments.(Click to show)In order to be charted you need to fill out this form:Username:CPU Model:Core Multiplier: [If you used Blck strap, put what Blck and mention your resulting frequency]CPU VID: This is the CPU core voltage value you input into BIOS.Vcore: This is the CPU Vcore reading from Hwinfo or HWMonitor under load. "Load" depends on what you're stressing.Uncore Multiplier:Uncore Voltage:Input Voltage: [aka VCCIN, Vrin, Eventual Input Voltage]Cooling Solution: [If you are delidded, note it here.]Stability Test: [Any test is OK, synthetic or not. IF YOU DO NOT LIST HOW LONG THE TEST IS RUN YOU WILL MAKE ME CRY.]Batch Number: [Malay or Costa Rica chip? Please list the entire batch number if you can.]Ram Speed: [Timings if you know them.]Ram Voltage: [If stock, ignore this.]Motherboard: [Optional. Not required to be charted, not required for picture verification.]LLC Setting: [If you didn't change default, say AUTO]Extra notes: If you ran a synthetic stress test like Prime or Linpack on adaptive and your Vcore is very different from your VID, I will ignore your Vcore because the number is useless. A Vcore under stress with override/manual voltage mode is useful, but with adaptive the voltage is totally blown up. Also, if you state that your uncore multiplier is "auto", I will write "34" instead.For the final picture verification column, you need to show a working picture to have it show "YES", otherwise it will be blank. The picture must contain the stress test, proof that the test was run as long as you claimed, AND it must also show HWmonitor or HWInfo's vcore reading. No, only VID will not cut it. Vcore. To be clear, I'm looking for the sensors part of Hwinfo, not the hardware overview which shows CPU and GPU logos. You do NOT need picture verification to be listed in the chart above, you only need it for the "YES" in the picture verification column.Amount of overclock submissions: 181===Problems? Ask here! Do not spend 5 minutes, tweak 2 things, get a bad overclock, and rage!Comments? I'd love to hear it!Questions? That's what this thread is here for!Suggestions? Go for it!Share it if you like it!Guide Last Updated: 5/31/14(Click to show)-Clean up mobo names in chart-Needs another overhauil to simplify the guide.-Add info about core temp variance from core to core.-Add into on 1344x/x/2014-Chart now shows last update time at upper left hand corner.-Added new VCCIN column in the chart.-Vdimm values now moved into the ram speed column, now renamed 'ram settings'.-Charting form now includes a pointer to note if delidded under 'cooling solution'.-Chart columns have lower width to help those with smaller monitors read it more effectively.-Now specifically noted what the x264 OCN link leads to.-Removed an old portion of the guide with wrong info.-Removed old, irrelevant info on x264 that now only confuses people.-Now includes Prime95 download links.-Fixed typos.4/6/2014-Charting form now includes me asking whether CPU is Malay or Costa chip.-Input voltage section has some revisions.-Edited delidding info.-Removed the line repeated where I said, set xmp off even if it's 1600.-Added info on Prime95 stopping while stressing.-Added 'ram voltage' column to charting form.-x264 download now includeds AVsynth and batch file in one download-x264 loop exe updated.-Override = Manual voltage noted.-Chart average voltage values now rounds to 3rd decimal place.-Added info about Gigabyte's ridiculous uncore ramping to x40 when set to stock.-Added more in-depth info on power states.-Added a quick note on Asus bios version.-Ring bus benchmark spoiler title changed to "Ring Bus Doesn't Matter [Evidence]1/16/2014-Greatly revised the old chart of stress test info and temps.-Added info on Cstates vs Adaptive mode. Any suggestion for using adaptive has been deleted.-Vrin/Uncore and its effects on temperature have been listed.-LLC investigation done and a new section included.-Removed extra unneeded data from Stress Testing section.-Revised total number of OC submissions.-Better numbered list implementation.-CPU voltage parameters cleaned up.-Input Voltage info listed twice, now fixed.-Added 'Why use this guide" part.-Added some new titled at the stress testing section for easier reading.-Last updated changed to guide last updated.-Included picture showing where Vcore reading is on Hwinfo.-Enlarged font at start saying not to stress on adaptive.-Started a change log.-Charting form now includes question for LLC.-Added point to check another settings for Asus mobos if looking for input voltage reading from HWinfo, courtesy of Veerk.-Fixed typo(s).1/7/2014Moved the input voltage info into its own seperate section and moved it up physically. That way more people will read it as it is more important than some other settings. Also clarified Input voltage info.-Added the 'Why are my temps so high?' troubleshooting tips under 'Stressing' section. Added tidbits on why a core is cooler than some other cores by up to 10C.-Added this new 'changes from last edit' section.-Revised total number of OC submissions, from 110 to 115.-Included extra note to use HWinfo is readings seem off.-Fixed typo(s).