cant get my 6100 fx-bulldozer to overclock past 4.0Ghz stable, what might be my problem?

deselator6

Honorable
Jul 31, 2013
3
0
10,510
Specifications:
Gigabyte 970A-DS3 AMD 970A
AMD FX-6100 bulldozer
8GB ram team group
ATI 4870 1GB
750W PSU novatech black edition
1TB seagate barracuda

im not sure what my problem can be, as when i put the voltages up another increment 3 out of 6 cores work and and the other fail the test, using prime95 to test my cpu
 

deselator6

Honorable
Jul 31, 2013
3
0
10,510


my cooler in a Antec H2O 620