I5 750 + gigabyte p55-ud5 problems

[alders]

So i have;

i5 750
Corsair H50
Gigabyte GA-P55-UD5
4GB Corsair XMS3 1600mhz
8800gt
Corsair 650W
windows 7 64bit

When i first built PC about a month ago everything was great, computer worked fine so i decided to overclock, i did a simple overclock on stock volts, turned all the usual stuff off, 166 BCLK, 8.0x RAM so it ran at 1333 (how it was with 133BLCK clock).

Ran prime95, was well within temperatures and no errors. Was fine for a week or 2.

Now all of a sudden my Prime95 constantly gets errors, i tried tweaking it so much, doing everything to get to pass prime95. Temperatures were like 50 max even with 1.3 volts and even highered my ram volt to 1.64 but couldnt get it stable,

So now ive updates BIOS put everything back to stock but it still fails prime94 on stock =/ i never get blue screen or anything, computer works fine, playing games, just on internet, all day nothing ever messes up, temps are always 50 or below atm im running rime95 there at 45 but worker 3 has already stopped, and im on stock!

ive disabled all power saving options, turbo boost, everything you can but everything on stock but still fails why???

EDIT: Also when it started messing up, my RAM was set to 1333mhz in BIOS, but when it posted it said 1328mhz :S

 

[alders]

never mind, i started checking all my cables etc, decided to check each RAM, turns out was one of my RAM sticks.

man my computer runs slow with just 2gb =/

 

[Deleted member 217926]

Yeah Windows 7 x64 really needs 4gb. It should scream when you get the new stick though!