Same problem here
AMD 8350 4ghz
Corsair 1866 8gb DDR RAM
GIgabyte 3gb DDR5 7950
SSD Drive
Latest amd drivers 13.11
Win 7 64bit
Attached is the GPU-Z report of what happens when the FPS drops
TIME , Mhz , Mem , Temp,fan,RPM , Load, VOLT
2013-11-02 15:20:30 , 1000.0 , 1250.0 , 65.0 , 79 , 3204 , 34 , 1.169 ,
2013-11-02 15:20:31 , 1000.0 , 1250.0 , 65.0 , 79 , 3207 , 30 , 1.169 ,
2013-11-02 15:20:32 , 900.0 , 1250.0 , 64.0 , 79 , 3206 , 13 , 0.950 ,
2013-11-02 15:20:33 , 501.0 , 1250.0 , 63.0 , 79 , 3206 , 41 , 1.069 ,
2013-11-02 15:20:34 , 501.0 , 1250.0 , 62.0 , 73 , 3016 , 47 , 1.069 ,
2013-11-02 15:20:35 , 501.0 , 1250.0 , 62.0 , 73 , 2985 , 11 , 0.950 ,
2013-11-02 15:20:36 , 900.0 , 1250.0 , 61.0 , 73 , 2985 , 10 , 0.950 ,
2013-11-02 15:20:37 , 900.0 , 1250.0 , 61.0 , 73 , 2988 , 14 , 0.950 ,
2013-11-02 15:20:38 , 1000.0 , 1250.0 , 64.0 , 74 , 3026 , 34 , 1.169 ,
2013-11-02 15:20:39 , 1000.0 , 1250.0 , 65.0 , 76 , 3088 , 34 , 1.169 ,
2013-11-02 15:20:40 , 1000.0 , 1250.0 , 65.0 , 76 , 3086 , 34 , 1.169 ,
@ 30-31 seconds the FPS is fine running 60fps+ on high setting
32 sec the FPS starts to drop i notice the Voltage drops from 1.169 and mhz Drops to 900mhz which is normal because 1000mhz is the boost.
However at 33-37 Sec the mhz drops down to 501mhz which shouldnt happenand seems like voltage drops as low as 09.50 and the GPU load is significantly less 10-14%.. this is when my fps drops to 10-12 for 5-10 seconds.
38sec the fps goes back to normal and is fine till the next drop in fps which is randomly around every 2-5 minutes