HELP!!! My computer hangs with a oc'ed 9550

[ah_sim]

Dear all,

I've got a overclocked 9550 by a local (HK) brand called grandmars. The card is using a 9600 pcb using TSOP 3.3ns samsung ram running at 450/600 default. I've exchanged my first card as the screen turned bad 15min after the computer started up. The second one ran fine on the testing machine when I exchanged the card. But when I used it with my computer it would crash right after the windows started.
I tried to pull out all the cards and added them one by one and I found out without sound blaster live, it ran way more stable (but still hang/reboot once an hour). I downclocked the card to 350/500 and it got a bit more stable but still crash once in a while. I suspected that there is some kind of conflicts between the motherboard and the card. My config is:

Asus A7V8X-MX
Grandmars Radeon 9550 Xtreme v2 (450/600)
Kingston DDR2700 512MB RAM
Texas Instrument IEEE card

Is it related to the AGP Bridging setting? I disable all possible feature in BIOS about AGP feature (e.g. AGP 3.0 recalibration). I'm using the newest driver from ATI. Thank you very much!

P.S.
This isn't exactly my card and the layout is the same. Thanks!

 

[venusbluejeans]

I had a similar problem with a overclocked 9550 card and found out it is the Via chipset on some motherboards. The graphics card and Via chipset do not get on together which causes the crashes. There is a way to fix it but it slows the communication between the two. Other option is to get a nforce chipset motherboard which I am about to do.