Problems With Disabling Integrated Graphics

[kajunchicken]

Ok, so this seems really bizarre. I just got a brand new 650ti boost and after I installed it I kept having stability problems. If I ran any Prime95 tests, my computer would crash. If I upped my RAM voltage to 1.65V, stability returned.

I was playing around with the BIOS some more and found out that if I re-enabled my integrated GPU, I could get the system to run stable with the RAM at the default 1.5V.

Any idea why disabling integrated GPU would cause instability?

System Specs:
Ultra 550W PSU (piece of crap. I know.)
Phenom II x4 B50 @ 3.1Ghz
2x2Gb DDR3 1333Mhz 8-8-8-21
Evga 650Ti Boost @ 1215/1592Mhz
M4A785TD-V EVO w/ HD 4200 integrated graphics.

I seriously have no idea what's going on. Help me out?

 

[omaroma11]

so you know about the a10 5800k apu I know that when you buy that cpu you need high end ram because ram is usually handled by the gpu but in that case it is handled by the cpu so I hope that somehow makes sense

 

[kajunchicken]

Haha that made no sense. No offense.

 

[omaroma11]

argh maybe this might help
http://www.youtube.com/watch?v=z0Z7H1PYUkk
SEE where I am getting it from

 

[kajunchicken]

argh maybe this might help
http://www.youtube.com/watch?v=z0Z7H1PYUkk
SEE where I am getting it from

I know about apu's being bottlenecked by ram. The problem I'm having is that my system is unstable when the integrated graphics is disabled. I have a perfectly good 650ti boost i use.