mystery stutter & falling FPS

wesmundo

wesmundo

wesmundo

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Joined
30 Mar 2007
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5
I just built a modest AM2 gaming system with a 6800GS and it's doing my nut in! I cannot get smooth 3D. No matter what I do, whatever I run starts out smooth and fast then rapidly degenerates to a choppy stuttery mess and runs half the speed it should, if that.

I can't score higher than about 8000 in 3Dmark03. This card is supposed to do about 11-12k I think.
In Rthdribl it starts out at a silky 80FPS then gradually falls to half that and worse, and chugs.
My P4 3.0 machine with AGP Radeon x1600 is about the same speed, and way smoother.
SiSoft Sandra benchmarks look good for CPU, RAM, HDDs

I closed all background apps. Moved static 1600Mb pagefile to 2nd HDD. Defragged repeatedly. I updated BIOs, XP, all drivers, DirectX. I checked for virus/malware/rootkits etc; it's a fresh install anyway. I even switched HDDs and clean installed tinyXP 'beast edition' (low resource build of XP) with bog-standard drivers off the original CDs.

I've tried countless combinations of old & new drivers, unplugged/disabled non-essential devices. I've under/overclocked the 6800 - it goes a bit faster/slower as expected but still stutters. Tried various rivaTuner2 tweaks and BIOS settings inc. defaults.
Nothing makes any noticeable difference!

I'm not getting artifacts/lockups/BSODs or any kind of instability (unless I OC too far).
Temps are fine, haven't seen the GPU go over 52c

I don't have suitable spare parts to swaptest with, but if I can figure out for sure which part (if any) is faulty I'll happily ditch it next payday :p
If my geforce is at fault, why does it run so quick at first?
If it's the PSU, why does unplugging devices & underclocking not help?

Cheers in advance for any clues, cos I don't have one!

-------pick out the culprit from this lineup--------
CPU - AM2 Athlon64 3800+ single core (stock)
mobo - Asus M2v, Via K8T890, single PCIe
1Gb RAM - 2x512Mb Corsair XMS2 6400 DDR2 (800Mhz, slack timings cos mobo only does 1.95v! )
VGA - XFX GF 6800 GS PCIe 256mb (clocks 485/1100)
PSU - Antec 350w truepower
drives - 1xSATA150 + 1xPATA + IDE DVDrw
onboard sound & lan
Win XP SP2
--------------------------------------------------
sorry for long 1st post!
 
ooof weird problem that!

Have ye not got any mates who will let you stick your graphics card in their computer?

At first I thought it may be a temperature problem but you said temps are OK. It could still be the PSU as graphics cards drink lots of juice so disconnecting a few devices might not be enough.

To be honest unless someone absolutely knows what this problem is we wont get far until you can try the card in another machine.
 
Deja-vu as far as the stutters are concerned! It was suggested at the time on forums when i asked that its probably the graphics card.

I had a socket 939 X2 4400+ / geforce 6800gt / 1 gig ram etc etc about 6 months ago. I had exactly the same thing where it starts off ok but got drastically worse pretty quickly and was ok again after a reboot, but again only briefly. I formatted etc trying all the service packs, nothing would sort it.

I tried allsorts to sort it, eventually i sold my x2 4400+ and downgraded to a single core 3700+ on the same motherboard, formated again and it was perfect, no jutters whatsoever. I thought at the time it must have been the fact it was a dual-core cpu, but maybe the cpu was just dodgy ?

I've since upgraded to a duos core intel E6600 , new mobbo , new gfx card and have never seen these problems since.

Unsure whether this is your exact problem but with mine even when i had fraps up and the game displayed 58fps on a 60fps game, it felt horribly juttery on a slight fps drop that normally would be barely noticable, it felt like 5 fps!!.
 
bobert50 said:
Worth noting is that i'm not thick and it wasn't v-sync tearing!! and i'm using a CRT :D
Click to expand...

Cant help the op sorry, but did you try the amd duel core patch? theres a known problem with duel cores and stuttering.
 
install coolbits reg patch then go play a game.

if there is stutter and stuff then exit the game.

then go into nvidia control panel and into the debug settings, and see if there is message there about SW silent running or something. i forget what it was.

if there is then post back.
 
Throttling!

Well strap me to a tree and call me Brenda! It IS a heat problem with the 6800GS. odd one though.

In rthdribl if I grab the window's title bar and hold it, the card pauses rendering. When I let go the FPS briefly shoots up then falls again - so the little sod must be throttling!

If I set the fan to 100% and clock the GPU down to 300mhz, the paused/non-paused FPS are the same - about 50 either way.
If I set the clock about 350-375 i start to see it throttling by about 10 FPS. If I go up to 400mhz or more it throttles so hard i get about 40 FPS difference or worse. So that it actually runs faster overall at about 325!
Pretty annoying since this model is supposed to run OC'd as standard, at 485/1100 - it's in the BIOS. When I had Coolbits active I let it autodetect max clocks and it recommended 522/1170! - I tried running that and got artifacts & lockups of course :rolleyes:
RivaTuner's hardware monitor says the temps aren't going above 52/53c, and it doesn't show the clockspeed changing - no wonder I didn't notice this before.
I downloaded Nibitor and in the BIOS the card is not supposed to throttle until about 100-odd degrees. I turned all the throttling temps up to max (145) and flashed it (scary!) but it still behaves the same. The modded BIOS has definately taken as I adjusted the default fanspeeds too.

I stripped the stock cooler (horrible white fibrous gunk on the ram) polished the ramsink quickly and tightened it right up with arctic silver. - no noticeable difference, though it hasn't had chance to bed in I spose.

So what's going on? Is the thermometer lying or being misread? Is there a 2nd thermometer that Rivatuner can't see? Cyber-Mav's comment about "SW silent running" is interesting - some kind of Cool'n'quiet-style nonsense? Will check that after work.
I just ordered an Arctic X1 cooler off OCUK - cheapie but should help. The original sounds like a hoover anyway! :p

cheers for all the replies!
 
thinking bout it, could it still be the PSU not letting the card reach full speed? I always thought it wasn't PSU cos I assumed that the card would either work properly is the power's good or crash altogether if the power's bad. I didn't think it might throttl if there aren't enough amps or something. Anyone know for sure?

As for trying card in someone else's PC; i think i'm the only one who's moved on from AGP! :rolleyes: I'm probably the nerdiest person i know :p
 
I've been trawling various forums some more and I reckon I have the "cold bug" and or 'Enable Write Combining' problem. I'm beginning to think i should have stayed with ATI :mad:
I will update when I know, just in case anyone else benefits.
 
FIXED!
well it was all down to dodgy cooling :rolleyes:
Why the stock XFX cooler was quite so bloody useless I don't know, but after installing the Arctic Cooling Accelero X1 I can't get the GPU to go above 50c no matter how hard I hammer it :cool:
I can hit 520/1150 easily (12k-odd in 3dMark03), and it's sooo much quieter. Very recommended.
I expect in summer I may come up against the throttling thing again, but there is a fix in the RivaTuner Power User options I read about.
 
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