Recurring Lag Issue

I have a PC plagued with a recurring lag issue. I first noticed it playing World of Warcraft, but my daughters also get it badly with other online games, too. It has slowly gotten more and more frequent now to the point where, I can log in and everything will be fine for a few minutes, and then I get massive lag spikes to the point of being unplayable. Frame rate drops to 1, give or take 1 or 2 and everything, including voice communication over Ventrilo, lags out and becomes useless. This lasts for about 90 seconds and then it instantly disappears and everything is perfect for a couple minutes, maybe as many as three or four minutes, and it happens again. Things I've noticed and tried: It only happens on this PC. None of the other computers on the router experience it. My wife's PC plays everything just fine so I do not think it is a problem with the provider. Changing ports on the router has no effect. Watching standard or HD video, such as a TV show on Hulu or movie trailers on Quicktime, does not have the problem. They seem to all be 3D games, like World of Warcraft or Toon Town. Site games like Nick Jr. don't seem to do it. Have noticed it on the load screen before connecting to the server to play, so suspect it may not be related to network at all. Upgraded to the latest video drivers for my card, posted just a few days ago, has no effect. Tried leaving the case open when playing to see if it is a heat build-up issue but the problem persists and the fan on the video card heat sink is running. Have cleaned out all dust buildup and reseated all of the memory and the video card. The PC is a Dell Dimension C521 with an AMD Athlon 64 X2 3800, 1.80 GHz processor, 2G memory, onboard NIC and Audio. I have installed a PNY NVIDIA GeForce 8600 GT video card w/ 512mb memory and using the digital video output. Any suggestions where to look next would be much appreciated. No five year old should have to know the words, "Mom, the horrible lag is back!" Thanks for taking the time to read my post!

Is this a new problem? Did these particular games ever work well on this computer?

As to specific games you might try this scan:

Can You Run It?

Yes this is a new problem. I installed the card to improve performance, mostly for gaming but also for video watching, over what the onboard video could provide. Initally, everything worked great and over the last few weeks this problem has crept in. It used to happen for a while then go days without surfacing. Now it is almost continuous. Tonight, it actually stopped doing it for about half an hour and then started again. Thanks for the link. Pretty handy little site and it says I pass the recommended minimums. This coincides with my experience that, before this issue started, things ran just great. My thinking is that maybe I've got a video card that's just on the fritz already?

Just to verify: When you loaded new NVIDIA drivers did you uninstall the previous driver first?

Just to verify:

When you loaded new NVIDIA drivers did you uninstall the previous driver first?

Bah! Rookie mistake. No I hadn't but I just tried it after reading this post. Uninstalled, rebooted, installed, rebooted. Unfortunately, it did not resolve the issue.

What is the Operating System? You might check out your Event Viewer for any coinciding errors.

Working with Vista’s new Event Viewer

How to view and manage event logs in Event Viewer in Windows XP

This PC is using Windows XP Pro. I'm assuming 32 but not at home right now so I can't verify that. I'll check the event viewer tonight and see if anything looks abnormal. I hadn't considered that. One thing I noticed last nite is that normal gaming operation runs the CPU around 60-70 percent but when the lag hits it drops to about 9-12 percent. That seems important but I don't really know what it's saying. I had assumed that I would be seeing the CPU maxed out when the lag struck.

UPDATE: I think I have discovered the root of the problem, now I just need to find a more elegant solution. A friend of mine asked me what the temperature of the GPU was and I couldn't tell. I visited NVIDIA's site and found they had some tools I could download which would show me. After installation, I discovered that the card's GPU was running over 120 deg C when it was under load and about 110 or so at idle. This seemed exceedingly hot to me, especially considering the graph the tools had defaulted to max temp of 90 deg C. My guess is the card has a 90 second reset on a thermal protection feature which is why the lag was so specifically timed the same every time it happened. I popped open the side of the case and rigged a fan up to blow across the video card dropping the idle temp to mid 60's and operating in the high 70's. Haven't seen a single occurrence of lag since. I have been investigating after market cooling solutions for GPU's and have run in to a road block in that it doesn't appear that any of them will fit inside the slim profile case on this Dell. Sigh… If anybody has any ideas for a cooling solution, I'd love to hear them! I'll update when I figure out something that works (or if the problem should return).

Good trouble-shooting work, Owl's Warder !

With those temperatures, I would certainly consider speaking to nVidia regarding a possible replacement.
But it might also be helpful to discuss the matter with Dell.

Slimline cases have some of the darnedest cooling problems!

Jephree will probably be along with a more substantial reply.
I just wanted to give you a hearty for your investigation and problem-solving.

Doug

They make standard PCI card fans that mount next to the graphics card for cooling but I cannot find a low profile model which would be necessary in a slimline.

I did find this although it exhibits one of the main issues with finding slim line hardware i.e. is it a half height bracket?

At 80mm it should be but I wish they would specify.

http://www.nexustek.nl/NXS-nexus-waveair.htm

I concur with Doug with your excellent investigation and problem solving.

Your card should be in the 60 > 70 range. This is standard for most Nvidia 8 series with stock fans.

As you can achieve this with your external fan experiment I would suggest your issue is simply case cooling.

If the link I posted does not prove promising to you you could also consider a case mod if you are at all inclined to cutting holes and mounting fans etc.