Sometimes after one hour,and sometime after 10 minutes,my system freezes,and my screen looks like this:

More information on my system:
Asus M4A89GTD PRO
Phenom X2 550 @3.1Ghz not overclocked
VGA set @ UMA+Sideport in bios-so usng onboard vga
all voltage controls except DRAM voltage are set to auto
DRAM is Corsair Dominator DDR3,TW3X4G1600C9D 1600MHZ(set @ 1600mhz,and 1.8V worked fine one my previous gigabyte gmt785-ud2h board).
CPU-temp 28 celsius
Chipset temp-31 celsius,everything sounding perfect except it freezes
1. First time it froze while unpacking a rar file,which wasn't very large.
2. time whilw browsing the web.
It passes small ftt's and normal stress testing in prime
Please Help!

More information on my system:
Asus M4A89GTD PRO
Phenom X2 550 @3.1Ghz not overclocked
VGA set @ UMA+Sideport in bios-so usng onboard vga
all voltage controls except DRAM voltage are set to auto
DRAM is Corsair Dominator DDR3,TW3X4G1600C9D 1600MHZ(set @ 1600mhz,and 1.8V worked fine one my previous gigabyte gmt785-ud2h board).
CPU-temp 28 celsius
Chipset temp-31 celsius,everything sounding perfect except it freezes
1. First time it froze while unpacking a rar file,which wasn't very large.
2. time whilw browsing the web.
It passes small ftt's and normal stress testing in prime
Please Help!













