I have purchased (2) of these boards, both experience video framing/stuttering during any 3D game.
AMD 64 X2 6400 (125 watt)
4gb DDR2 Ram
Tried (3) different video cards (all from different Companies, Nvidia,ATI ect..) including the onboard video, same results.
Tried different ram/os (Vista/XP)/power supply, same results.
10 second stutter, 5 seconds good, repeats until exiting any of the games.

Seems to be something on the board causing this issue, has anyone had this problem with this board?
Have trouble ticket open with Asus, but they send the generic check list of items to check. They have not admitted that there may be an issue.

I suspect that this board is experiencing a circuit overheat due to cpu voltage. I am waiting for a 65 watt cpu to test this theory.

I suspect that this may be a MB circuit overheat issue with the AMD X2 6400 (125 watt cpu).

All voltages are well within specs, but I have noticed that upon cold boot, before MB gets warmed up, that I can play games stutter free for about 1.5 to 2 minutes before stutter cycle begins.

Tried GeForce 6600 video, same issue, so I do not believe this is a driver issue.
Still no word from ASUS.

Update:
Well,
Running (3) games on (1) core did not correct stutter, in fact, it caused the games to freeze instead of stutter during 5-10 second cycle.

Installed AMD Power Utility, noticed both cores running at 100% during stutter, and 50% when running smooth.

ABIT MB will arrive tonight for testing, using current cpu from problem ASUS MB, I will post results.

Also have AMD X2 5000 (65watt) cpu set to arrive Friday for testing, will post results as well.

ABIT AN-M2HD LE nvidia Geforce 7050pv MB arrived, installed cpu/ram/video from ASUS board into same case used for ASUS.
Reinstalled XP Pro SP2.
Installed games for testing.
Works great. No stuttering at all.
Only part changed out was the MB.
Looks like ASUS has some questions to answer. I would not recommend this board to anyone. May be just a bad batch, but they should at least admit that this is a problem as I have (2) of these boards with the same issue.

Tried an AMD Athlon X2 dual-core 5000+ (ADO5000DSWOF) 2.6ghz black edition w/1mb x 2 cache 65nm 65w (brisbane) in an attempt to prove my theory, tested, works great, stutter is gone.

Apparently ASUS does not support this cpu.....

I have an AMD 6000+ CPU and Asus MB's always make this high-pitched "dog-whistle" sound when they run. In my experience, no other MB's do this. It is VERY annoying and when I call Asus, they act like it is the first they have heard of this problem. I have noticed it with 3 MB's in a row.

I have given up on Asus for now.

I have spent 2 weeks trying to resolve the same problem - graphics are choppy and stuttery. Have tested by changing graphics cards, drivers etc. It has to be the motherboard. I hate this motherboard! And I am not happy.

I had the same exact setup and the same exact problem. Asus finally told me that the motherboard does not support that CPU - that the voltage regulator can't do the 125 watts. I bought a Biostar mobo and put the 6400+ in there, now it flies and works like a charm. Goodbye Asus.

Thank you so much for this thread! I've been trying to figure out what the problem was for a week. Guess I'm shelling out more money on this system for a new mobo. Had a feeling that 125 watts was going to byte me in the butt eventually.