[Linux] Sudden FPS drop

rkfg

For no visible reason FPS drops significantly to 15-20 midgame, r_stats shows high GPU waiting (flapping from 30 to 150 ms). I thought it was something with GPU overheating and throttling but it's not that, temp is less than 60°C (for my 560 GTX it's quite cool). Fortunately switching to Fullscreen Windowed and then back to Windowed immediately fixes that and I have 35-60 FPS again. Fullscreen Windowed has noticeable worse performance for me, 10-15 FPS less than just Windowed. I'm playing on almost everything maxed up except atmospherics, AA and AO. Here's log.txt: http://pastebin.com/W0p9q2sp

IronHorse

May not be related, but I experienced similar things with DX11 this week, internally, and linked it to message popups in my system tray (win 7) from a syncing tool i had.
NS2 doesn't play well with overlays at all, so that made sense..

Are you able to reliably reproduce this?
If so, please get a plog:

Type p_logall in the console (the ~ key) when you are playing a game with others.
Around at least 5 minutes of capturing your issue, quit the game and navigate to your hidden %appdata%/natural selection 2/ folder and then compress/zip the plog file. (the file type will show as ".plog")
Upload that file on the internet somewhere and link it here please

This will give me a frame by frame analysis of every single thing that's going on, and what is causing the low FPS.
Thanks!


EDIT: That path obviously doesn't pertain to you, since you are running linux, so wherever linux stores your log.txt thats where you will find this plog. Alternatively you can name your plogs too.. p_logall testingfps in the console will make a file called testingfps.plog

rkfg

It happens from time to time quite randomly, it may happen or not in any particular match, often in a heat of battle with many players from both factions in one room attacking each other. The problem is that FPS stays low even when I look at the wall and no one is near. Mouse also lags badly, sometimes it's like 500+ ms lag.

But it's reproducible enough. I did some plogging and analyzing but didn't find anything useful, most of the time was spent on DrawIndexedPrimitives so it's inside the driver I guess. Those plogs were very short and inaccurate and the FPS drop was not that big that time so I'll try again and post them. Also, is there a way to stop p_logall without exiting the game? Found this here: p_endlog Ends the log started with p_logall and writes it to a file
May help somebody one day, I've searched the forum for this to no avail.

rkfg

It happened today (<15 FPS, >500 ms mouse lag) and I have the plog: http://www.mediafire.com/download/6ucsixq7wvx63cm/plog.7z

As I said there's nothing interesting there, an obvious GPU load. I heard GPU coolers went wild and it may point to overheating and throttling but immediately after I've switched the fullscreen mode to Fullscreen Windowed everything became fast, smooth and quiet. It was after I've stopped the logging so it's not there. I can only guess but for me it looks like a heavy redundant rendering which is reset after the display mode change.

I also noticed that I had Compton (compositing manager) running, I'll try more without it. Can't remember if I used it before when I had an FPS drop.

IronHorse

Interesting..
Thanks for the legwork

Might be worth running a realtime log on what your system is accessing when this occurs to see if some overlay or background app is accessing the GPU, making NS2 unable to recover from it. (is there an equivalent to processexplorer for linux?)

rkfg

I think it's compositing. After turning it off I had everything running smooth (at least in a couple of games). I heard there are similar issues with compositing on Windows so it may be related. I use Compton for one single purpose — VSync in HTML5 and Flash videos on youtube and alike, for some reason proprietary NVIDIA driver has VSync bugs for a long time. Turning on VSync in game (double buffering) cause noticeable FPS decrease (not just cap it to 60 FPS but sometimes lowers from 50 to 42 or so), so it's not worth it. Compton maybe does the same, I may check it to be sure. It grants VSync working everywhere in the system regardless of apps settings.

There are various monitoring tools available on GNU/Linux but I'm not sure what I should look for. I have no overlays except the Steam one (which shouldn't be a problem as was discussed before) and overall my setup is pretty simplistic. I'll try more tests with some compton's options.

eyeris

rkfg wrote: »

Turning on VSync in game (double buffering) cause noticeable FPS decrease (not just cap it to 60 FPS but sometimes lowers from 50 to 42 or so), so it's not worth it.

Before you draw any conclusions about any particular set of video settings you should try exiting the game and starting it fresh with those settings. I can run at about 80 FPS with max video settings but sometimes if I decrease the video settings, even to the minimum settings, my FPS will drop to a range of 10-25 until I restart the game. This is on GNOME 3.8 w/ compositing on.

rkfg

That's right, I'll try this. But anyway I turned VSync on and off and FPS went up and down accordingly. Also when VSync is on there's a small but annoying mouse lag. Or maybe it's my imagination.

IronHorse

Vsync, by it's very nature will incur some degree of mouse input delay beyond the baseline, just fyi.
Let me know what you discover though in regards to this FPS drop (if it continues to point to composition)

@eyeris
Interesting observation, i've heard reports of opengl doing this before in NS2.. will look into it.

rkfg

I suspect compositing is involved here. I even had a first crash today playing as an alien comm, pressed A for cysts and it has crashed. Turned compositing off and played several games in a row without problems.

Also tried in-game VSync and had like 30 FPS cap, it only raised to 50 near the walls (it was ready room which always has nice FPS). After turning double buffering off it stabilized near 45.

rkfg

Turns out it wasn't compositing. Now I had it on Biodome without compton running. Here's the plog: http://www.mediafire.com/?383f89mk6b543x4
It contains playing with low fps and then switching to fullscreen and back after which I've had 40-50 FPS. Interestingly, now most of the time is spent inside the Present method instead of DrawIndexedPrimitives as it was before with compositing enabled.

rkfg

A little final (probably) update on this. After lowering textures to medium I don't have drops anymore even with almost everything else turned on. So I guess it's throttling after all and technically game has nothing to do with it.

IronHorse

Can you confirm this by running a log on your gpu while playing a full game? (like with MSI or something)

NeXuS

My GPU was throttling just a few days ago. I would go from having 100-140 fps down to 30 or so for about 15 seconds. All I did was clean my fans out really well. Have you checked that?

rkfg

@IronHorse what sort of confirmation would it be? I have not even a single drop while on medium textures with almost everything on, just some minor slowdowns (but without lags) when really much is happening on the screen. On the opposite, I have occasional drops with heavy lags when on high textures with everything else turned off except texture streaming. Which case are you interested in?
@NeXuS I see no overheating regardless of texture setting. It's on 70-72°C in game and throttling happens or not strictly because of lots more of texture data as I see it. 560 Ti allows up to 98°C as specs say. But anyway I can run nvidia-smi -l on the tablet via SSH to check it without switching windows. It cools pretty fast in 5 seconds after lowering down the stress.

manatee

@rkfg

I also have the 560 ti. Usually have +100 fps on lower settings. Then, not every time but some times, when the skulks attacks me, I experience a fps drop to like 15-50 fps for a very short period of time, like for a hundred of a second.

rkfg

Well, I've solved this issue in a radical way — bought GTX 770. Now I can play on ~40-60 FPS on all high (including AO, AA and atmospherics) but I've realized that although the effects are great, they obstruct the view making everything less contrast and a bit blurry. So I turned off bloom, AO and atmospherics having 60+ FPS almost all the time, no drops and lags at all. Fancy graphics are good for demos and streaming (as a spectator) but not for the real gameplay, unfortunately.

IronHorse

Bloom doesnt really hurt so much, imo.. but yea AO has inherent mouse input delay, and atmospherics blocks your vision.
Glad that its fixed... but i still wonder if it was based on /exclusive to the 560ti..

manatee

IronHorse wrote: »

Bloom doesnt really hurt so much, imo.. but yea AO has inherent mouse input delay, and atmospherics blocks your vision.
Glad that its fixed... but i still wonder if it was based on /exclusive to the 560ti..

Was told to turn off draw damage in general settings and that worked really well havnt experienced any more of those short freeze lags at all. But it is abit annoying though not being sure of how much damage you do.

NeXuS

Draw damage is a big part of the teamwork. I wouldn't turn it off. Telling teammates how much damage you did to a higher life form is very helpful.

manatee

It is really like night and day, the difference where I can the win the standoffs between small groups of skulks and even higher lifeforms. I will most likely not turn it on again. But yeah I get your point, trapping them and so on based on intel.

But, I've not always had this problem. Ive been playing a long time without any problems at all and this just appeared a couple of weeks back.

I play on:
i5 2500k 3300mhz
16gb 1600mhz ddr3
asus gtx 560ti

And I havent noticed anything else about it getting slow or that something is wrong with it. Also monitored cpu and gpu temp while playing, cpu max 79 celsius and gpu max 60-70 i think. I also uninstalled all programs installed from 2 months back until today.