Asus Radeon 3870 X2 problems

[hushbrown]

I have just bought an Asus Radeon 3870 X2 1gb and am having problems running any 3D Mark benchmarks. Every time I disable the Catalyst A.I setting my computer would run it fine however I am getting a low score of 12990 when my computer performed better on the same system with a Geforce 8800 GTX and got in the 14000. However when I enable the Catalyst A.I to either standard or advanced I get higher frame rates but everytime it reaches the second test ( the firefly test ) my whole computer would just crash and restart. Why does this happen? and also Im hearing small buzzing noises around my graphics card. dont know if it is my card or something else on the computer but Ive never heard it before until I installed this video card.
I am running:
Intel Core 2 Duo E6850 @ 3.5ghz
Gigabyte X38 DQ6 Motherboard
4gb G.skill ram
2x 500gb Seagate hdd in Raid 0
Asus Radeon 3870 X2 1gb
Creative X-FI Platinum Sound Card
Gigabyte 800 watt PSU

 

[Gavin_Capacitor]

So, what OS are you running? is it a hard restart or is there a blue screen? If it was a blue screen did you debug the crash dump? do you have the 8.3 catalyst drivers?

 

[hushbrown]

thanks for replying! im running windows vista ultimate 64bit edition and it is a hard restart... no blue screen.. just shuts down and restarts. and yes i do have the 8.3 Catalyst drivers. it is very frustrating as i know this is a good card but cant even see any results

 

[kpo6969]

Do you have the 8pin pcie connection hooked up?

 

[hushbrown]

i have both 8 & 6pin power connection hooked up, i have a Gigabyte X38 DQ6 motherboard which includes a PCIe 2.0 connection just in case the card runs off 2.0 which it doesnt.
Its just everytime i enable Catalyst A.I everything crashes, from games to 3D Mark benchmarks. when disabled everything works fine