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CrossfireX HD 7770 unequal GPU usage

Last response: in Graphics & Displays
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December 3, 2012 12:47:43 PM

I have a Sapphire AMD HD 7770 and a Asus AMD HD 7770 2gb dual fan, after successfully crossfiring the cards ad enabling it through CCC there is a huge difference in bus widths and bandwidths of both cards, the Asus cards shows bus width as 128bits and bandwidth as 73.6GB/s where as the Sapphire card shows only 32bits of bus width and only 18GB/s of bandwidth,the card in the 1st PCI-e slot is the asus one and the other is occupied to the sapphire one and the DVI cable connecting my monitor is connected to the Asus card, I have latest drivers installed.
My system specs are:
Processor-i5 2500k
PSU-Crosair GS700(700watts)
RAM-corsair Vengeance 4X2gb @ 1600mhz
mobo-Asus Maximus V Gene
HD-Seagate barracuda 1TB @ 7200RPM
and sony 22x optical drive

And yeah even when gaming I dont see any significant difference whether CF is enabled or disabled, please help :( 
a b Ĉ ASUS
December 3, 2012 1:22:08 PM

Sounds like you are operating in x16/x4 mode, vice x8/x8. What does CCC indicate?
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December 3, 2012 1:27:08 PM

ok I am not too used to with using CCC where can I check it in CCC?
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a b Ĉ ASUS
December 3, 2012 2:33:23 PM

Look at the hardware info for each GPU.
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December 3, 2012 2:43:07 PM

both are running at pci-E 2.0 X8 which is also the max my board can support
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a b Ĉ ASUS
December 3, 2012 2:57:27 PM

OK, that is good. If you swapped the positions of the 2 GPUs, does the info change as well?

Also, keep in mind that both will not operate at an equal utilization usage all of the time. Last, what resolution are you gaming at?
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December 4, 2012 9:35:22 AM

I am gaming at 1366X768 which is the max that my monitor supports.
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a b Ĉ ASUS
December 4, 2012 11:20:44 AM

That is the problem. At that resolution, you aren't even maxing out a single HD7770 in most cases. If you pushed the resolution to 1920x1080, you would see both GPUs more fully utilized.
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December 4, 2012 12:16:01 PM

Seems like I need to buy a new monitor but what about the fps I mean the lower the resolution the higher is the fps thats what ive heard
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a b Ĉ ASUS
December 4, 2012 1:29:34 PM

Not necessarily. You get into an area of where (at the lower resolutions) you are CPU or GPU bound. Needless to say, but your GPU isn't operating at its peak efficiency when used at the lower resolution.

Also, the particular games you are playing have an impact here as well. What are you playing?
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December 5, 2012 9:05:46 AM

Ive been playing battlefield 3, PES 13, COD MW3, black ops 2, assassins creed 3,far cry 3.
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