Processor: Intel Core i7-920 Bloomfield 2.66GHz LGA 1366 130W Quad-Core Processor Model BX80601920
Motherboard: ASRock X58 Extreme LGA 1366 Intel X58 ATX Intel Motherboard - Retail
Memory: OCZ Gold 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) OCZ3G1600LV6GK
Video Card: HIS H577F1GDG Radeon HD 5770 (Juniper XT) 1GB 128-bit GDDR5 PCI Express 2.0 x16
Power Supply: CORSAIR CMPSU-650TX 650W ATX12V
Hard Drive: Western Digital 500GB SATA 7200RPM
Operating System: Windows XP Pro 64-bit
The 6-pin plug is connected to the video card and have the latest drivers for the video card.
For some strange reason my FPS in Call of Duty 4 single player drop to 30-40fps. It doesn't matter what settings I have on (I put them on the lowest to test), the FPS in fighting scenes goes to crap. I noticed that in the first part of 3dmark06, the FPS did the same thing (drop).
My 3dmark06 scores: 16081
SM2.0 Score: 6168
CPU Score: 5309
In settings: 1280 x 1024
HLSL VS Target: 3_0
HLSL PS Target: 3_0
Repeat Tests: Off
I see what you're looking at: HIS Driver Download Page, but I can't help notice that the HD5770 is not listed on ATI's web site for Windows XP-64. My guess would be that while the drivers you downloaded do work, they're just not optimal for your OS. My recommendation would be to wait until ATI develops and delivers drivers for your OS.