There's an interesting issue with certain Linux CPU governors that will actually bring down performance in Vulkan games. You might not need this, depending on what CPU governor you have installed.
You might end up seeing jerking or micro-stutter, far more than you would in OpenGL games. The issue is that when using OpenGL in games, you're generally taxing a single core of your CPU due to less multi-threading. With Vulkan spreading the load more, your CPU isn't being used so much.
The Linux CPU governor takes that as an opportunity to bring down your CPU performance, as right now it's not the smartest bulb in the tanning bed.
Here's what a Croteam developer said about the issue:
QuotePowersave governor is an awful choice for playing games. It may quite be the case that it's not happening for OpenGL especially because GL runs slower.
When the game is running fast enough that CPU has to wait on the GPU, the governor sees that as an opportunity to downclock the CPU, or put cores to sleep. The jerking is a result of the CPU throttling up and down very quickly.
In general, CPU governors on Linux are much, much dumber than the Windows one. (It seems that Windows overrides the throttling for all 3D apps, or similar.)
That's why we have this warning in the log. Switch over to Performance governor, at least while playing.
So a tip for now when playing Vulkan games on Linux: Set your CPU to high performance mode, you can do it like so in terminal ("performance" is just an example, see more here):
echo performance | sudo tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
A higher performance mode will generally result in higher power consumption too.
Then to set it back to normal. You don't need to use "powersave" see more options here, as it's just an example. According to the Arch Wiki you likely want "ondemand" for AMD:
echo powersave | sudo tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
You can find out what performance mode you're in right now by running this in terminal:
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
My default on the Intel i7 5960x is powersave, for example.
Hopefully this issue will be fixed as more games come over to Vulkan. It would be nice if developers didn't need to code around issues like this on Linux.
http://www.faqs.org/faqs/unix-faq/faq/part4/section-7.html
Regarding the frequency governers for Intel CPUs:
These governors are *not* comparable to the regular pstate driver for Linux (e.g. used on older Intel Cores and AMD Cores). Intel implements its own policies in the driver that are independent of the cpufreq policies. Thus cpufreq policies will *not* work as expected. Details can be found here:
https://www.kernel.org/doc/Documentation/cpu-freq/intel-pstate.txt
This driver especially does *not* honor additional cpufreq settings apart from max_freq / min_freq.
Total War:Attila:
OnDemand: 22.7 Ave FPS, Performance: 33.9 Ave FPS
Total War:Warhammer:
OnDemand: 57.7 Ave FPS, Performance: 74.0 Ave FPS
CoH2:
OnDemand: 27.8 Ave FPS, Performance: 49.2 Ave FPS
Dirt Rally:
OnDemand: 51.6 Ave FPS, Performance: 101.3 Ave FPS
Deus Ex: Mankind Divided:
OnDemand: 40.6 Ave FPS, Performance: 50.5 Ave FPS
Edit: Better layout.
Last edited by FredO on 23 March 2017 at 6:27 pm UTC
Quoting: buenaventurashedutil <--- INTRUIGING, what is this? I google and it seems like some newfangled stuff? I wonder if that will be even better than Performance!If you want to use the 2.4GHz with schedutil governor add intel_pstate=passive in the boot kernel line. I'm using it and my hasswell cpu in the laptop has lower temperature than using only intel_pstate (powersave / performance) when there's not much load.
Still, why does it only go up to 2,00ghz? Says right on the sticker on my lappy "up to 2.4 ghz", bullshiet :P
buenaventura Mar 23, 2017
Quoting: EikeQuoting: buenaventurashedutil <--- INTRUIGING, what is this? I google and it seems like some newfangled stuff? I wonder if that will be even better than Performance!If you want to use the 2.4GHz with schedutil governor add intel_pstate=passive in the boot kernel line. I'm using it and my hasswell cpu in the laptop has lower temperature than using only intel_pstate (powersave / performance) when there's not much load.
Still, why does it only go up to 2,00ghz? Says right on the sticker on my lappy "up to 2.4 ghz", bullshiet :P
Well my CPU is an AMD A8-6410, so I guess I can't do that right?
I still wonder how I can get it to be 2.4 and not just 2. You would think that that would make a difference.
But I always had the CPU-Indicator in Ubuntu and therefore never had troubles changing it. I also do it for other CPU intensive stuff. I still have to take a closer look at schedutil.
Quoting: marcushttps://www.kernel.org/doc/Documentation/cpu-freq/intel-pstate.txt
plain text in 2017? common! i'm a human being! i hate being Treated as a machine!
Quoting: GuestQuoting: elmapulplain text in 2017? common! i'm a human being! i hate being Treated as a machine!Feel free to register unreadablecrap.com and publish there all the documentation you can find in an unreadable tiny font with a choice of colors that makes the readers blind within five minutes.
why? they already did that with this plaintext.
Quoting: elmapulQuoting: GuestQuoting: elmapulplain text in 2017? common! i'm a human being! i hate being Treated as a machine!Feel free to register unreadablecrap.com and publish there all the documentation you can find in an unreadable tiny font with a choice of colors that makes the readers blind within five minutes.
why? they already did that with this plaintext.
The display of plain text is up to your browser/you. Some Strg-+ makes it already look nicer here.
Power-Metal-Games Mar 24, 2017
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