26/9/2018 update: added touchscreen bug

I originally reviewed the XPS 15 9570 (FHD) in June of this year, scoring it 4/5, so if you haven’t read my original review, I suggest reading that first here.

Too often, products are reviewed in the first few weeks of release, assigned a score, and never touched-on by media again. This blind spot means that the daily experience of the average end-user may be wildly different than that of the reviewer.

There’s no general aim of misdirection intended; it’s just the result of tight deadlines and the fact that we can only use so many devices at once.

In this case, however, I am able to report on the XPS 15 9570 as I’ve been using it daily for the last 3 months. In light of these experiences, I would like to share my observations about the device and how I would rate the product after spending hundreds of hours on it.

The Good

Let’s start with the good.

The 4K XPS 15 still has the best display I’ve seen on a laptop. The resolution, color accuracy, contrast, brightness, and evenness on my unit strike me every time I use it.

The CPU performance is still excellent (especially after an undervolt), posting numbers 15-20% higher than your average i7 or i9 15-inch 2018 MacBook Pro.

Battery life is generally quite good, hitting 8-9 hours on a full charge without worrying too much — in fact, I don’t believe I’ve ever run out of juice on a single day of work since I’ve had the notebook.

The TrackPad is very pleasant to use, and the keyboard is quite decent as well. It’s no ThinkPad, but I can type quite comfortably on it for long periods without feeling fatigue.

Lastly, port-wise, I appreciate having both Type-A, Type-C, and SD card ports, meaning I don’t need to bring adapters with me everywhere.

The “Meh”

About 3 weeks after getting my XPS 15, I noticed an occasional rattling noise coming from the left side of the computer. It was intermittent, only noticeable at lower RPMs and only when the GPU was active. After examining the fan, I diagnosed it as a bad bearing, called Dell, and 2 days later a tech came to swap the fan for a new one. No fuss, no muss, no downtime.

I would have been more annoyed had I not had the next business day premium warranty, however — something I have learned to never skimp on.

The Bad

Unfortunately, there are a host of issues that have popped up and remain unresolved for the XPS 15 9570. Some of them are specific to the 9570, while others have plagued the whole series for years.

The first of these is what is known as high DPC latency, and has been well-documented on the XPS 15 series for years. DPC stands for Deferred Procedure Call, and it is used to set the priority of different tasks for execution.

A high latency is a problem primarily when playing audio, especially in real-time, because it results in crackling and popping audio. As a DJ, this is job critical, but it’s also very disruptive to the average user who just wants to play media through the built-in speakers. Dell seems to be aware of the issue (caused by ACPI.sys), but there is no fix as of this moment. There are some workarounds, such as toggling Spatial Sound on and then off again, but nothing fixes the problem for good. This means that playing live audio from the XPS 15 is a no-go, precluding musicians, producers, or DJs from using it for professional purposes.

The second biggest issue I’ve noticed is the generally non-functional state of Modern Standby for this machine. Dell originally shipped the XPS 15 9570 with both traditional (S3) Standby and the newer phone-like Modern Standby. The first problem is that Modern Standby is broken: Every time I put the machine to sleep, I take it from its sleeve some time later to feel the chassis is quite warm, and upon waking it, I can see that I’ve lost somewhere between 2-10% per hour. Other times, the machine simply doesn’t wake up and needs to be hard-reset. I’ve tried to diagnose what might be causing this, first replacing the included Killer Wi-Fi with an Intel 9260 card and then running sleep diagnostics, but I’ve received no answers.

This is made worse by the fact that Dell removed regular (S3) Standby in BIOS update 1.3.1. As I noted in my original review, using “proper” Standby resulted in some bugs and glitches involving the screen and the CPU. Rather than fix these bugs in S3 Standby, Dell decided to remove the feature altogether, forcing everyone to use the completely broken Modern Standby. The current situation essentially forces anyone who needs to conserve their power throughout 1-2 days to hibernate their laptop every time they are not using it. Lenovo’s flawed X1 Carbon Gen 6 had similar issues with Modern Standby, and so returned the option for traditional Standby in a recent BIOS update. In comparison, Dell’s handling of the problem thus far is unacceptable.

Even worse, from BIOS 1.31 update onward (currently at 1.4.1), Dell quietly began throttling the GPU at only 74C rather than the 78C the machine previously was limited to. I will try to be fair and assume this is not out of malice and manipulation of early benchmark scores and instead guess that perhaps there was another reason for this change. However, there was nothing mentioned in the BIOS update notes about this and no reason for the change was given. Since the XPS 15 9570 is a thin and light notebook, the GPUs have always run quite close to their prioritize temperature of 78C. Cutting this temperature limit down to a very conservative 74C will significantly impact the performance of the GPU as a result.

Additionally, the 1.4.1 BIOS — which cannot be downgraded from — seems to have introduced yet another severe bug: the touchscreen stops functioning after the laptop is put to sleep. To get this functionality back, the laptop must be restarted.

A final annoyance is that the CPU seems to have issues with idle power consumption. Instead of idling at around 0.7 W as intended, the CPU is often found to be unable to enter a lower C-state for some reason. The result of this is the CPU idling at significantly higher levels of power consumption, between 2.8-4.0 W. This has a significant negative impact on both battery life and idle temperatures, as it increases the idle drain from what should normally be 6-7W to 12-14W total system-wide consumption. This can be temporarily fixed by putting the computer to sleep and waking it, but it will happen each time the laptop is restarted. I’m not sure if this is a Windows problem, Intel problem, or Dell problem, but at the end of the day it’s Dell’s product that I paid nearly US$2500 for, and the ball is in their court to make the product work as it should.

These last two issues in conjunction lead to an almost farcical reality: the XPS 15 9570 now must be put to sleep in order for the CPU to properly enter low power states, but doing so will break the functionality of the touchscreen.

Conclusion

I gave the XPS 15 9570 a score of 4/5 in my initial review, noting that despite its flaws, it’s still one of the best all-around notebooks money can buy. This is still somehow true, but these issues remaining with the machine nearly 6 months after launch cannot be ignored, and I would now rate the XPS 15 9570 more like a 3/5.

Dell can and should do better to iron out these issues, and I hope that we can see some progress in this area in the next few months. In the meantime, I will be giving the new ThinkPad X1 Extreme a shot, so keep an eye out for my review where I match the X1E up against the XPS 15.