computers – randomprocess

If you have a Surface Pro 4 or a Surface Book, chances are, you’re experiencing pretty awful sleep (Connected Standby in particular) battery drain. This power state is designed to enable connectivity and near-instantaneous wakes, while consuming extremely little power think 10 days of battery life, in this state).

In order for this state (Intel calls the system state S0ix, or an active-idle state) to work, a combination of operating system, system firmware, and device drivers need to all act appropriately. The Intel integrated graphics devices appears to be a common cause of battery drain in sleep for Skylake-based systems. Sleep study reports (you can view them by running “powercfg sleepstudy” from an elevated command prompt) indicate the graphics device is active on the order of 15-17% of the time, while in sleep, causing 1W+ drain.

However, an updated Intel graphics driver, released December 22, 2015, version 15.40.14.64.4352, has improved that somewhat for my Surface Pro 4. Check it out – can you guess when I installed the driver?

sp4_sleepstudy

Power draw is still not where I’d like to see it (from my work on various SoC platforms, within Windows, I’d expect these Core-based systems to consume in the range of 100-150mW, on average), but it’s still a 40-50% improvement from where it was. This high drain is also likely why the Surface team implemented a rather short doze-to-hibernate timeout of 2 hours. It means I’m frequently resuming the device from hibernate (~12 seconds) instead of from Standby (<1 second).

The driver is currently only for 6th generation (Skylake) Core graphics and with a Surface, you’ll need to install it manually via Device Manager (great installation guide, at Windows Central), until Microsoft pushes it to this particular device ID via Windows Update. It seems to work just fine, though. If you’re seeing similar (better) results, let me know!

The Surface Book. It was an exciting moment to watch Panos unveil a premium laptop (finally!) and, shortly thereafter, pull the display off its keyboard base. With only a few weeks between launch and hard availability, anticipation and excitement has been maintained. I even stayed home to await delivery, the morning of October 26.

There are 3 important aspects that drew me to the Surface Book:

All the trappings of an excellent laptop (weight, size, battery life, display)
Form factor versatility
Discrete GPU for light-medium gaming

I have lots to say about the Surface Book, but I wanted to dwell on the last point, first. I’m not a heavy gamer, but I do enjoy some strategy games, occasionally. I’ve compromised that capability in my laptop choices, to date, as I value weight and mobility more. So, needless to say, I was eager to see how the Surface Book would handle those gaming scenarios.

Microsoft (and NVIDIA) continue to remain mum on the particulars of the discrete GPU. It was announced as a Maxwell-based part, with 1GB GDDR5. Now, this is a combination that has never been seen before and, interestingly enough, Panos spoke to its use primarily as an accelerator for professional content-creation applications, such as AutoCAD and the suite of Adobe tools. Yes, some light gaming was also mentioned, such as League of Legends, but with the Surface Book’s hardware and price points targeting prosumers and content professionals, no effort was made to match, performance-per-dollar, gaming laptops.

With Surface Books in the wild, we know that it’s a GM108-based part, with 1GB GDDR5 @ 5GT/s. The 940M-equivalent GPU disappointed some, but I also expected the GDDR5-enabled bandwidth to improve performance, not insignificantly, over the standard DDR3 configuration. Here’s a spec comparison. Note the 940M core and memory speeds vary, based on design implementation.

gpu_table

With 2.5X the memory bandwidth, we should see some substantial improvements. I’ve compared game performance, across a few titles, using an 840M (from which the 940M is rebranded), the Surface Book’s integrated Gen9 HD 520, and the discrete Surface Book GPU. Framerates are average and game settings are as follows:

Bioshock Infinite – 1080p, Medium setting
Total War: Attila – 1440×900, Performance setting, Shadows – Max Performance, Texture – Medium
Shadow of Mordor – Surface Book @ 1500×1000, 840M @ 1536×864, Low setting

surface_book_gpu_benchmarks

Across these three games, all of which have built-in benchmarking tools, the Surface Book dGPU is 2X faster than the integrated and anywhere between 20-33% faster than the 840M/940M, from which it is derived. It does stand that in many games, like Shadow of Mordor and Attila, in the tests, 1GB VRAM limits you to lower texture fidelity, compared to 2GB; in practice, the GM108 isn’t fast enough to drive those higher textures at sufficient framerates for a good experience, anyways.

While all of this pixel-pushing is going on, the fans (both in the clipboard and in the keyboard base) spin up to varying degrees. They make their presence known primarily by a rushing, whooshing sound, and limited amount of high-pitching whine, which makes the noise more bearable than most caused by small-diameter fans and blowers.

So, you can play some games on a Surface Book, as well as it use it as a pretty slick multi-use productivity machine, otherwise. But, I as found out over the subsequent couple weeks of use, it has its share of teething pains.