Very strange performance problem

cybertronix · Posted: Thu Oct 19, 2006 3:44 pm Post subject: Very strange performance problem

Apologies in advance for the long post, but I have a lot of symptoms and I've tried quite a bit of stuff so I wanted to mention all of it.

I've recently started having some weird performance glitches in various games. For instance, Doom 3 engine games are hitching badly and even at 800x500 I can't sustain 60 fps. It runs exactly the same as at 1680x1050. UT 2004 last night was running as though it had a 50 fps cap because it wa sitting right at 50 no matter what I was doing or looking at. It wasn't doing this a short time ago and AFAIK I haven't messed with any settings. Wine games don't seem to be performing as well as they used to either (CS:S and Far Cry), but since that's Wine I can't say for sure what's at fault. There's definitely hitching in CS:S that's similar to what I was seeing elsewhere though. The only game I've tried where I haven't noticed any significant problems is Savage, but on my internet that game lags enough that I might just not have noticed it hitching.

The first time I noticed this was after a Wine and kernel upgrade to get Far Cry working, but even after reverting to my old kernel the problem remains (I didn't bother reverting Wine because that wouldn't affect Doom or UT). I'm also running the 9626 nVidia drivers, but the 8774 (and 9625) didn't solve the problem either. I've tried running stuff from TWM with nothing else running, but still no luck.

The only possible culprit that I've been able to find so far is my power supply. It's a Thermaltake that is strongly recommended against for my motherboard (heck, I might as well just list all of my hardware, the list is here - first system), and I noticed that something is running hot on my motherboard (not sure what because I'm pretty sure that they're mislabelled in lm-sensors), but looking in the BIOS I think it might be the PWM IC, which as I understand it regulates power for the motherboard. I'm replacing the PSU anyway because the fan controller cable just broke so now the fans run at full speed all the time, which on this thing is extremely loud. I'm just not sure that would be causing these symptoms. BTW, I did back off my overclock to stock, and it lowered my temps but the problem remains. Maybe something got fried already though.

I'm also getting a backtrace in dmesg resulting from an "IRQ handler type mismatch for IRQ 3". So far I haven't found anything about it though.

I've updated to the latest of all my software and done a revdep-rebuild to make sure I wasn't having any library problems.

I'm really stumped by this. The 7600 GT is pretty new, but I'm almost positive that it wasn't doing this when I first bought it. I played around with quite a few different settings and games just to see what kind of performance increase I would get out of it. The only possible correlation is that I seem to recall the framerates in Quake 4 being a bit inconsistent when I turned on AA, but now they're a problem even without AA. I can stare at one thing and my framerate will be anywhere from 60 down to 20 with no apparent logic to explain why.

Help!

xanas3712 · Guru Joined: 15 Oct 2004 Posts: 455

I think the problem may be with the widescreen resolution on quake4, because I have the same issue on my system with a widescreen 24" acer display. However, when I run in 1600x1200 (looks stretched) it seems to alleviate the problem (this is with a 7800 GT)

I had always noticed that under widescreen my performance was lower than my sister's 6600 GT system, which obviously didn't make sense even though she was running at a lower resolution (1280x1024) also.

UT2004 may have something to do with vsync, 50hz being something those widescreens are set near.

I'm not sure on the wine games though, I haven't played CS:S in linux yet to speak for it.
If the PSU can be an issue for this kind of thing it might be mine too, mine is an Antec but it's only 350 watt which is well under-powered for a 7800. I wouldn't think you should have such a problem with only the 7600 though, but who knows.

What do you get in glxgears by chance?

cybertronix · Posted: Thu Oct 19, 2006 7:44 pm Post subject:

Mad Merlin · Veteran Joined: 09 May 2005 Posts: 1155

cybertronix · Posted: Fri Oct 20, 2006 2:56 pm Post subject:

cybertronix · Posted: Tue Oct 24, 2006 5:52 pm Post subject:

Well, new power supply same old problems. I'm still getting really bad framerate drops in Doom 3, even on the menu screen. At one point it was having long pauses every few seconds, but that may have been related to forgetting to remodprobe nvidia after recompiling it because of a kernel switch.

I did get rid of the IRQ error in dmesg by disabling some unnecessary stuff (the serial port was probably the culprit based on the stack trace), but that didn't help my problems.

I guess tonight I'm going to play with turning apic and lapic back on, but I'm not real confident that will help especially now that the IRQ conflict seems to be gone. Plus I seem to recall hearing that nForce4 boards have trouble with them which is why I turned them off in the first place.

BTW, is it normall to have th ERR line in /proc/interrupts be so large? I see that nvidia is sharing an interrupt with USB, but I don't know of a way to change that manually. Maybe a BIOS setting?

bunder · Bodhisattva Joined: 10 Apr 2004 Posts: 5934

just a sidenote, i don't believe the SMP binaries work. i've run quake3 and et in smp mode but the game turns it off or says it wasn't enabled at compile time (or something heh)... can't say i've tried doom3, but i doubt it will work either.
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Mad Merlin · Veteran Joined: 09 May 2005 Posts: 1155

cybertronix · Posted: Wed Oct 25, 2006 2:28 am Post subject:

Yeah, I don't really expect that I'm terribly CPU limited in any of these games. If I were I would just turn up AA/AF until I wasn't.

Tried turning back on apic and lapic, no effect. It got rid of the big number on the ERR line in /proc/interrupts, but even with nvidia having it's own IRQ there I still have problems.

I guess I'll run memtest overnight tonight and see if that finds anything. Otherwise I'm pretty much stumped. Suggestions?

cybertronix · Posted: Wed Oct 25, 2006 2:52 pm Post subject:

Memtest found nothing. I guess tonight I'm going to try an install of another distro to a spare partition to see if it's software or hardware related.

cybertronix · Posted: Thu Oct 26, 2006 2:50 am Post subject:

Well, it looks like this isn't Gentoo-specific. I was getting the same weird framerate drops in Mepis too. Guess maybe I should go hit up the nvidia forums and see what they have to say.

Incidentally, can someone tell me if this is normal?
http://www.nemebean.com/stuff/weirddoom3.png
The left side of the O is strange and there are black dots on the right side of the message box. I don't think those things should be there but it's kind of hard for me to test at this point.

Oh, and going from no AA to 4x 9-tap Gaussian only made a 4 fps difference (56-52) in the timedemo. Seems kind of small to me.

Mad Merlin · Veteran Joined: 09 May 2005 Posts: 1155

It's possible that your video card is overheating and clocking itself down to prevent damage, that would explain the visual artifacts at least. Try adding more airflow over the card.
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Game! - Where the stick is mightier than the sword!

cybertronix · Posted: Thu Oct 26, 2006 2:29 pm Post subject:

That was one of the first things that came to mind when I saw the artifacts, but according to the thermal monitor it's not even hitting 60C when I'm in a game and the throttling threshold is 115C. The other thing is that I'm almost positive that when I swapped the 6600 GT back in it did the same thing too, but that was working fine when I took it out. I guess I'll have to do some more card swapping to make sure.

But if it's not the card, and it doesn't seem to be the software, about the only thing left is the motherboard (again, this is eerily similar to what happened last year that prompted me to buy the motherboard I have now :evil:

) and that's the only thing that I can't easily eliminate as a culprit.

Mad Merlin · Veteran Joined: 09 May 2005 Posts: 1155

The power supply could also be faulty, or you're drawing more load than it can handle. Are you using the same power supply as you were with the old motherboard?
_________________
Game! - Where the stick is mightier than the sword!

cybertronix · Posted: Thu Oct 26, 2006 5:49 pm Post subject:

Well, I was. I actually just got a new one this week that can easily handle my system (OCZ GameXStream 600), but the old one was pretty frowned upon by DFI so I guess it's possible that it trashed something before I got rid of it.

kreamie · n00b Joined: 27 Oct 2006 Posts: 3

I have a strange problem as well. My ut2004 is capped at 50 fps. I've tried changing resolutions and all different kinds of settings such as vsync etc. My system specs are athlon xp 2800 1 gig pc2700 ram nvidia 6800 gfx card. My old ati card ran ut2k4 better than that. If anyone can tell me some things to try I'm open to any suggestions! Thanks.

cybertronix · Posted: Fri Oct 27, 2006 4:16 pm Post subject:

You might want to check ~/.ut2004/System/UT2004.ini and make sure all the vsync options are off in there as well. I don't remember what they are all called but if you grep -i vsync it should show you all of them. Not sure how they would have gotten turned on if you didn't do it, but you never know. Particularly since I don't recall finding an in-game setting for vsync.

On the other hand, if I could keep it at 50 fps I'd be happy. My problem now is that my performance is maybe on par with my old 6600 GT. Oh well, I guess I'll just turn down the res for the LAN tonight since barring a miracle this isn't going to be resolved by then. Sometime I want to try the other PCI-E slot on my mobo too. I think it's running at only 2x, but I'm curious to see how it would perform anyway.