[Mesa-dev] [Bug 84570] Borderlands 2: Constant frame rate drops while playing; really bad with additionl lighting

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=84570

--- Comment #21 from Kai <kai at dev.carbon-project.org> ---
(In reply to Andreas Hartmetz from comment #19)
> I've noticed that disabling CPU frequency scaling makes a big difference in
> the severity of micro-hangs (3.17, dynamic lights off). My explanation is
> that, when threads are waiting for each other, the scheduler doesn't know
> that the apparently "idle-blocked" threads would all run faster overall if
> the CPU went faster. Doesn't matter if that's wrong, the difference is
> there...
> 
> At least on AMD (some Intel CPUs use a special frequency scaling driver),
> you can effectively disable CPU frequency scaling like so:
> echo performance | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
> 
> Maybe that also helps a bit with dynamic lights on?

I have that Intel pstate driver for my CPU, but after feeding the performance
setting to scaling_governor the amount of drops goes down, the drops aren't as
severe (usually around 17 FPS and not single-digits; only exception: the first
five to ten seconds after loading screens) and the overall FPS rate is up by
~5-8 FPS. Thanks a lot for that tip!


(In reply to Ian C. Bullard from comment #20)
> (In reply to Kai from comment #18)
> > That's quite possible, though I can see drops (as shown in the attached
> > screenshot), when I do nothing particularily intersting besides moving
> > around in an area which I've been in for some time. The really bad drops
> > (single-digit) indeed seem only to happen upon entering an area, ie. after a
> > loading screen.
> 
> The drops can occur even if you've been in an area for a while.  Borderlands
> is a heavily streamed game so new textures/shaders can cause a hiccup. 
> We're looking at ways to smooth this out.

Thanks for clearing this up. Though I like to state that using the radeonsi
driver with the stack detailed in comment #15 gives you a very playable game
(almost no drops) with "DynamicLights=false" and only the smaller drops I
described in comment #18 with DynamicLights=true. From my POV that sounds like
"supporting" Radeons with the FLOSS driver should be ok or at least not worse
than nVidia cards. Especially when combined with Andreas' suggestion.
I've been playing for a few hours (alone and co-op) with this stack and
DynamicLights=true and it works for me; if you keep DynamicLights off it should
work for most, shouldn't it?

> > Though I did hear from a friend – using a nVidia card with the proprietary
> > driver and DynamicLights=false – that she's seeing occasional
> > drops/micro-freezes as well.
> 
> That fits with what I expected and matches what I said above. 

Oh, I thought your previous statements only related to Intel and AMD GPUs
(especially since nVidia is the only officially supported GPU vendor).

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/mesa-dev/attachments/20141015/e493af5e/attachment-0001.html>