Low GPU usage when running CPU @100% with Prime95...

[K1LLER HORNET]

I've just payed about overclocking my GPU & thought I'd put my system through it's paces with a couple of stress tests.

I ran Prime95 on the blend setting stressing CPU & RAM making my 2600K sweat a bit, and ran EVGA's OC Scanner to get my GPU running as close as possible to max.
However, I found that while the CPU was maxing itself out, the GPU was held back by something. It seemed to hover around the 50-60% usage figure and occasionally sometimes below that.

Any ideas why this is?
My rig is in my sig.

 

[Gregster]

Can you run something like 3DMark11 or 3DMark Firestrike?

 

[TheRealDeal]

I've just payed about overclocking my GPU & thought I'd put my system through it's paces with a couple of stress tests.

I ran Prime95 on the blend setting stressing CPU & RAM making my 2600K sweat a bit, and ran EVGA's OC Scanner to get my GPU running as close as possible to max.
However, I found that while the CPU was maxing itself out, the GPU was held back by something. It seemed to hover around the 50-60% usage figure and occasionally sometimes below that.

Any ideas why this is?
My rig is in my sig.

Were you running the prime95 cpu and ram test at the same time as the evga oc scanner test. If so then your gpu was being bottlenecked by not having enough cpu power to push it to the max.

 

[andy_mk3]

Furmark will get it going

 

[K1LLER HORNET]

Were you running the prime 95 at the same time as the gpu test. If so then your gpu was being bottlenecked by not having enough cpu power to push it to the max.

I was running them both at the same time.
Guess you're right. Prime95 hogged all the bandwidth.

 

[TheRealDeal]

I was running them both at the same time.
Guess you're right. Prime95 hogged all the bandwidth.

Yea your cpu is more than enough to push a single gpu to the max in every game/benchmark.