Overclock unstable after windows 8.1 install

[maxmw]

I overclocked my asus gtx 670 a while back on windows 8 using MSI afterburner and I got the card stable at +145 core clock and +570 memory clock i ran several benchmarks including heaven benchmark and it never crashed. Then yesterday I upgraded to windows 8.1 and i ran the heaven benchmark which now crashes very early in however the strange thing is that my card still seems stable in games and on furmark (which i ran at 1920x1080 for half an hour) were does not crash. Do you think I should just leave my overclock and ignore that it crashes in heaven or should i maybe increase the core voltage on the card to increase stability (I want to avoid reducing the clock if possible) ?

Thanks in advance

 

[chaparral]

(I want to avoid reducing the clock if possible) ?

Thanks in advance

Youe most likely getting lower FPS and more stutter/lag if your card overclocked right up to it max limit or past it limit..

 

[Kaapstad]

Some things run better in Win8, some better in Win7.

 

[maxmw]

so would it be best just reduce it until heaven is stable?