Wavy lines / flicker in 3D apps only?!

Hi, I have a 22" Acer LCD screen with only VGA connection and have been having trouble when playing all the newer 3D games like Far Cry 2 and Assasins Creed. I get faint wavy lines that scroll vertically at crazy speeds, but only when I am looking at certain dark coloured textures. eg. when swimming or at dawn in far cry 2.

When I take a screen capture (ctrl + print screen) I see it stop momentarily.. I paste the image into MS paint and the exact same image shows NO wavy lines, so its only when in a 'Real Time' 3d application!

just to note, I changed the monitor cable and got slightly better results (alot less noticable while swimming in far cry2). It cant be a ground loop because the problem isnt there with a screen capture of the offending image.

Changed my graphics card from 8600gt to 9800gt and it got a bit worse!
Also, I dont have any exaust fan for removing the extra 9800gt heat, could this be the culprit?


here are my specs:

Steel mATX case
Asus M2n Mx SE motherboard AM2
Amd athlon 64 x2 4000+
2gb Corsair XMS2 RAM
480w PSU for system
250w PSU for video card (ThermalTake w0099)
XFX 9800GT 512mb (625mhz core no overclocking)
1 x IDE HDD 40gb (dont laugh)
1 x IDE DVD R/W

any help would really be apreciated!

Mark

My first thought would be heat problems. You might try installing SpeedFan or GPU-Z or something to monitor your video card temperatures. See what your temperatures are when these events are occuring.

You could also use RiverTuner or similar program to adjust fan speeds on your video card (default speeds are usually kinda low to keep noise down).

You could also try updating video card drivers (or reinstalling) if you determine you don't have a temp issue.

Since you had this problem with both cards, I'm inclined to believe it's more of a temp issue than a card problem.

In 2D mode (desktop stuff) your video card runs a bit cooler. Once you fire up 3D stuff like games, is when the GPU in the video card really starts doing its work, therefore creating more heat.

i am using 178.24 drivers, are there any known issues? because it doesnt happen in older games at all, its only games like UT3, Farcry2, Asassins Creed all the newer ones..

What are the best drivers that are rock solid stable?