GTX 970 power issues

[Gdog96]

Hi

 

I have recently bought a KFA2 GTX 970 second hand, however I noticed a strange issue when stress testing it. 

 

If I stress the GPU using MSI Kombustor, the GPU power and usage will both be at or around 100%. However, the moment I begin stress testing the CPU at the same time (using prime95) the GPU usage drops to 30-40% and power to 55-60%, resulting in a massive drop in FPS. 

 

I tried using MSI Kombustors CPU burner but it only made this effect worse with power and usage dropping to 40% and 20-30% respectively. 

 

I assumed this was my power supply causing the issue as its only a 450W silverstone SFX unit. However, I tried the GPU in my friends PC with the same specs and a Corsair CX600 power supply and I found the same issue.

 

Is this normal? What can I do about it? Generally pretty confused at the moment, would love some input from you guys. 

 

Thanks 

[19_blackie_73]

Hi

 

I have recently bought a KFA2 GTX 970 second hand, however I noticed a strange issue when stress testing it. 

 

If I stress the GPU using MSI Kombustor, the GPU power and usage will both be at or around 100%. However, the moment I begin stress testing the CPU at the same time (using prime95) the GPU usage drops to 30-40% and power to 55-60%, resulting in a massive drop in FPS. 

 

I tried using MSI Kombustors CPU burner but it only made this effect worse with power and usage dropping to 40% and 20-30% respectively. 

 

I assumed this was my power supply causing the issue as its only a 450W silverstone SFX unit. However, I tried the GPU in my friends PC with the same specs and a Corsair CX600 power supply and I found the same issue.

 

Is this normal? What can I do about it? Generally pretty confused at the moment, would love some input from you guys. 

 

Thanks 

i notice that effect too but not that big. But i think it is normal BECAUSE: the cpu gives the gpu the information what to do. If the cpu is maxed out, it won't be able to give commands to the gpu what to do so the load will break in.

[AdamH96]

Don't run both tests at the same time... they're not meant to do that.

[Monarch]

If you run CPU and GPU stress tests at the same time you're going to run into a bottleneck. Your CPU is busy with its stress test so it can't fully feed the GPU, which is why its usage drops. This is perfectly normal.

[Gdog96]

Ah okay, thanks for explaining it to me everyone, i appreciate it!