Amd 6790 bottleneck?

[marl24]

greetings Tom's Hardware community... i'm new with Amd's gpu and i'm surprised that i was able to overclocked my xfx 6790 from 840/1050 to 990/1250 run eugine Heaven dx11, and 3dmark11 (passed), but i noticed in gpu-z (sensor) the core clock stays at max 775 even @100% gpu load using furmark v1.9.1(xtreme burn-in check & 4x MSAA anti-aliasing) also 1920x1080 res. Is this perhaps a bottleneck for my current setup because it does'nt show 900 core clock @ max gpu usage?

intel Q9550 @ 3.38Ghz (highest stable overclock)
Generic 4GB 800Mhz DDR2
xfx 6790 @900/1250 overclock (default 840/1050)
Delta psu 750W

Opinions are much appreciated... Thank you.

 

[deadjon]

It certainly isn't a bottleneck, and I personally have never heard of a GPU dropping core speed for any reason other than to idle. Your PSU shouldnt be throttling a 6970 either.

 

[marl24]

This why i feel strange with this result so i'd rather revert to default clock speed to measure it, but even @ default core clock it stays there 775 max and idle about 100Mhz... is there something i'm missing? thanx again

 

[deadjon]

Re-install drivers?

Re-flash the BIOS (Do this at your own peril)

I got nothing at the moment. Thats really weird

 

[marl24]

Not tried yet (drivers)... bios? i'm afraid that i can't re-flash coz every time i flash it...error occur something like id rom incorrect if i'm not mistaken, i had Msi P7n diamond sli motherboard... let me try re-install drivers when i got home.

 

[deadjon]

Oops, I meant reflash the GFX card BIOS xD

 

[marl24]

tried to re-install drivers but no luck... went to xfx support center and i found a update for vbios for my gpu.

According to them "HD6790 XFX Version 1.2 BIOS to Fix the wrongly shown clocks when in 3D - HD6790 XFX Version 1.2 BIOS to Fix the wrongly shown clocks when in 3D"

I downloaded and tried to install but again i cannot flash it (DOS mode) then worst thing happen.... restart and viola! Bootmngr is missing pls blah blah blah.... Let me try to reformat my hdd hope this will help.. thank you again.