Performance drop after few minutes

[carpand]

So I got my system OC'd and stable. (1 hour on both OCCT tests and 5 hours on prime95 blend) at both 3.7ghz and 3.8ghz.. Have 2 profiles for my setup in my bios. Here is the problem. After startup I can run benchmarks fine, they run great and scores look good. I'm using super pi, amd overdrive, and cinebench.

After about 10-15mins after startup.. my performance drops by almost 10% easily.. some cases upwards of 20%. I have my power options set to max power consumtion/performance.. I don't understand..

Please any thoughts?

PS my specs should be in my sig to see my setup

 

[carpand]

Dropped my NB from 2.4 to 2.2ghz.. haven't noticed a performance drop in benchmarks and so far seems to have solved my problems.. Might have to bump my cpu back to my 3.8 OC and try the lower NB =D

 

[overshocked]

could it have been heat? What were the temps?