GPU Overclock becoming considerably worse?

[fishingcat]

My HD 7870 XT was originally capable of overclocking easily to 1200MHz core and 1600MHz memory, both of which are reasonable values for this card.

However, I recently noticed that my card was downclocking to it's power saving state whilst playing games (501MHz core clock), negatively affecting performance.

After playing with my voltages and clocks it's apparent that I can't raise the memory clock to 1600MHz anymore without downclocking or driver crashes, and I can't raise the core clock above 1175MHz without artifacting or drive crashes.

Voltages seem to make little difference.

Any explanations as to why this might be the case, or a possible solution?

 

[Nuwidol]

Its getting hotter now. Partly due to the weather & partly due to the card becoming dusty inside your rig.

 

[fishingcat]

That doesn't explain it, because the temps are still low (sub 70 degrees at full load for core, sub 60 for VRMs) and increasing the fan speed to lower load temps makes no difference.

 

[MichaelM]

Updated drivers recently? If new drivers increase the GPU and memory usage then it puts more stress components and can change the stability range of an overclock.

 

[fishingcat]

It's possible that the performance hit coincided with the installation of the 13.3 Beta 3 drivers, but I doubt they would have an impact his significant.

 

[Meaker]

As drivers take more use of a chip the slowest transistor in there is going to be stressed more and is more likely to fail.

 

[fishingcat]

Welp, I just updated to the 13.4 beta drivers so I guess I'll see how that goes.