Codename "Zambezi" – AMD FX Series



Gulftown/Sandy Bridge/Phenom II/Zambezi - Click on image to enlarge ​



Click on image to enlarge ​



Click on image to enlarge ​



Click on image to enlarge ​



Click on image to enlarge ​

After being teased for oh so many years, Bulldozer is officially here. As mentioned in the introduction, AMD have sought fit to re-launch their vaunted FX series branding, which has historically only been used on the highest-end enthusiast-oriented hardware. While the consumer desktop chips are all part of the FX series of products, their codename is Zambezi, a name which was taken from one of the longest rivers in Africa. This is actually an apt moniker, because as you read about later on, the Bulldozer microarchitecture has some very long pipelines.As you can see, the processor itself retains the same look and dimensions as the previous generations, but what lies underneath the integrated heatspreader is radically different. Before going into any specific details it should be highlighted that as was the case with the Llano APU's , AMD simply could not have manufactured these Bulldozer parts without having made the move to GlobalFoundries new 32nm manufacturing process. The Zambezi CPU die features over 2 billion transistors, which is a whopping number when compared to the 758 million of the Phenom II X4 and 904 million of the Phenom II X6. Just as a point of reference, Sandy Bridge comes in a relatively svelte 995 million transistors, while the six-core/twelve-thread Gulftown clocks in at 1.17 billion transistors. Transistor counts are obviously not what most people are interested in, so let's dive right into the juicy specs outlined on the tablet below:Clearly, on paper these new chips look terrific. They all have very high default clock speeds and/or can Turbo up to very high levels. Many of the models have gotten a small northbridge frequency bump (up from 2000Mhz on Phenom II), they all sport a much faster HyperTransport Link interface (up from 4.0 GT/s), have native support for DDR3-1866 memory modules. Perhaps most impressively these Zambezi processors have a truck load of cache (up to 16MB in total), and some fancy new instructions that are more advanced then anything that Intel will have to offer for the foreseeable future. The TDP numbers are about what we would expect, which is to say identical with previous generations, but then again AMD always overestimates heat output.These new processors look even better when we focus on the price. $245 for the top of the line 8-core CPU that can turbo up to 4.2Ghz? Deal of the century, right? Not so fast, this clearly shows that AMD lacks a little faith in their flagship part, since its not willing to go head-to-head price-wise with the four-core/eight-thread Core i7-2600K, which typically retails for about $315. It is however in direct competition with the $220 Core i5-2500K, a four-core/four-thread part. As you will see in the coming pages, they ultimately made the right decision...kind of. By the way, today AMD are launched the FX-4100, FX-6100, FX-8120, and of course the FX-8150 that is the focus of this review. Expect the other models to launch in the not too distant future.Before we get into any discussions over the microarchitecture and performance, let's take a quick look at the new packaging for the FX-8150, as well as closer look at the chip itself.As you can see, AMD has totally overhauled their packaging when it comes to Zambezi, at least with regard to the flagship part. The FX-8150 will ship in this 5" x 5" x 3" metal container with a standard heatsink that looks quite similar to the one that shipped with the Phenom II X6 processors. As has been leaked in these past few weeks, AMD is indeed planning on releasing a SKU with a closed-loop liquid cooler, similar to the Corsair Hydro series, which should be available shortly after launch. We will be getting our hands on one in the coming days.As you can see, our chip was manufactured in the 35th week of 2011. That is a three full months later than our recently reviewed A6-3650 APU sample . This is some very fresh silicon. Like every other AMD processor in recent history, this part's CPU die was manufactured at Fab 1 in Dresden, Germany and assembled in Malaysia.Although it would take an expert to spot it, these new processors actually have two additional pins when compared to Phenom II's , it still fits in the standard AM3+ socket. Zambezi wasto work with AMD's newest 9-series chipsets, but it should also work on socket AM3 motherboards, but that will obviously depend on motherboard manufacturers releasing compatibles bioses...and whether they properly designed their motherboards to deal with the higher power requirements that an 8-core chip requires. On a site note, those of you considering purchasing a Zambezi processor should take a look at this blog post from AMD , just to ensure that you have a painless upgrade process.With Zambezi, the lowest idle clock speed has been increased from 800Mhz to 1400Mhz in order to lessen the latency when ramping up to a higher performance state. This is a neat little idea, and it should come in handy since the FX-8150 can ramp up to an impressive 4200MHz. As you can see, the chip's core voltage changes radically depending on the performance state, but our sample topped out at 1.380V, exactly the same as our Phenom II X4 but lower than the 1.44V level of our Phenom II X6's. Obviously every chip will be different, but this gives you an indication that AMD really put high frequency above lowering power consumption. Although our engineesing sample doesn't have a revision listed, we believe that it is a C2, which is what all retail chips should be.Next up let's take a closer look at the new Bulldozer microarchitecture that forms the basis for these Zambezi processors.