Strange 'glitching' - possibly CPU issue

[AndrewC]

Hi all!

I have been having problems for a while with my current PC. Although there are a few different issues I believe they are all caused by a single problem:

1) Window Media audio exhibits random pops and bleeping.

2) Strange compression artifacts in TMPGEnc video conversions (MPEG-1 and 2) Example image: http://www.geocities.com/avp_knite/problem1.gif

3) 3D graphics are simply not rendered correctly. For an example of this see: http://www.geocities.com/avp_knite/problem2.jpg . Note that this image is a mild case, and graphics seem to tear and warp all over the place. This is abundant in 3DMark and occurs with less frequency in actual games, except Doom 3 which is rendered completely unplayable (sob!).

4) CPU fails tests in CPU check software (but this does not necessarily mean it is the CPU?).

I have a feeling it is either the CPU (an AMD XP2400+), the motherboard (MSI KM4M-L) or the RAM (256MB 333MHz DDR), but I don't want to fork out any cash unless I know I am replacing the correct component. Ideally I would like to be able to fix the problem(!). I have tried clocking the RAM down to 266MHz to match the CPU frequency but this does not help. The CPU runs a little hot, about 60C, but I have read that MSI motherboards are known to do this, and the temperature only reaches about 65C when under stress. The PC does not crash outright so I don't think the CPU is overheating.

I have been pulling my hair out trying to sort this out, so if anyone has any suggestions or has had a similar experience I would appreciate it if you could let me know!

[Catweazle]

Hi Andrew,

Your processor is running too hot for sure. Was that my system I'd be ripping off the heatsink from the processor, cleaning the chip core thoroughly with metho, and fitting a decent 3rd party heatsink to it using Artic Silver 5 thermal paste instead of the crappy stuff that AMD recommends. I've done just that to a 2400+ system of my own that was running too hot, and it's worked wonders.

Leave that RAM at the same speed as your FSB, because your system will be faster like that than if you have it at a higher speed ;)

But most of all, have a look at your display card. That 'tearing' in the picture you linked is indicative of a video card that's overheating or overclocked! Check your system first, of course, and make sure you have the most up to date drivers installed for motherboard and display card, and make sure you have DirectX up to date as well. Format and install clean, for preference, so you can eliminate software problems and system file corruption as a possible cause.

Snowy artifacts and image tearing is bad, mmkay? If all the things mentioned don't fix it, then you might have to fit a new heatsink/fan to the display card, or even replace the card altogether.

[AndrewC]

Thanks for the suggestions.. this is what I've done:

Replaced the graphics card: Was a LeadTek GF3 Ti200, now a proper Nvidia GF3 Ti500. No difference to the symptoms, so I assume this isn't the problem.

I've got a fan blowing into the case. The temperature of the CPU drops to about 50C idle but this doesn't seem to help either. I put some thermal grease on the CPU as well. It looks silvery so I assume it's not just silicone.

Thanks for the advice on the DDR frequency :)

I went through DirectX 9.0 and 9.0b before I got fed up and reinstalled windows XP with SP 1a. Now I'm using DX 9.0c.
My graphics drivers are the 61.77 ones from the Nvidia site, so they ought to be OK.

I should have mentioned that the actual 3D tests in 3DMark 2003 seem to be OK (albeit very slow - that's what I get for running a GF3 :-). It's the CPU tests and ragtroll that cause the real problems.

Is it possible that the CPU is damaged in some way? I don't have a problem buying a new heatsink/fan for the processor but if that doesn't work I'm out of options!

"Snowy artifacts and image tearing is bad, mmkay?" - Just to clarify, I don't get snowy artifacts in 3D apps. That would make me certain it was a video card problem. And yes, they are bad! Especially when Doom 3 is staring me in the face and I can't play it properly :(

[Catweazle]

It could be the processor. You need to ensure that traces of previous thermal interface material are completely cleaned from both processor die and heatsink botton. I scrub my own ones with metho several times, because it's the indetectable traces in microscopic sufrace 'pits' that create problems. The type of thermal paste used is important as well. some cheaper 'silver coloured' pastes are actually as bad as the cheap, white silicone based crud. Shin-Etsu or Arctic silver5 should be the materials of choice, and they should only be used in tiny amounts. Less than the size of a grain of rice is the amount to use, and it should be carefully soread to cover the surface of the central die core only, in an even layer.

But I really do think that looks like a display card problem, and I wonder if the display card heatsink itself needs to be removed and the thermal paste on that replaced as well.

[AndrewC]

Well I've installed a ThermalTake Silent Boost, and I used the thermal compound provided with it, because I can't seem to get hold of any arctic silver. I cleaned both the CPU and heatsink surfaces with Aksa 'CPU and heatsink cleaner' and a lens cloth (from specsavers ;-).

There is NO change in temperature, which is odd to say the least.

I can't imagine it's still the graphics card because I replaced the whole card! Also, with the fan blowing in the case surely that would have corrected the problem? TMPGEnc certainly isn't using the GPU to do it's calculations and I get tons of artifacts all over the video. This graphics card has a heatsink and fan on the GPU, and heatsinks over the VRAM. I appreciate where you're coming from but there's too much evidence against it being the graphics card in my opinion.

Like I said in my first post, this motherboard (MSI KM4M-L) seems to run CPUs very hot. See http://forums.amd.com/index.php?showtopic=16062 for an example of what I'm talking about. My question is: Should I replace the CPU or the motherboard? I don't care how hot the thing runs as long as it ends up working properly.

[AndrewC]

Managed to fix the problem!

The CPU was damaged and needs replacing. Tried a different CPU and the symptoms vanished. Will require cash throwing at it, but not the end of the world :p