The system would post and BIOS reported all components including 4g of ram just fine, but the problem would consistantly occur when I was trying to install Windows 7; while installing the OS, or more specifically while 'Expanding Files' during the installation, I would get BSoD saying either "IRQL_NOT_LESS_OR_EQUAL" or some dll files are missing. So I then ran memtest86 for multiple passes to make sure it wasn't the bad memory; both sticks reported no errors while being tested individually or together.
So I thought perhaps it was a simple incompatibility issue so went ahead and picked up 2 sticks of Corsair XMS3 ram which I tested with memtest86 even before I tried installing Windows 7 again and found to be error free. But the exact same problem would occur still during Win7 installations.
I updated the BIOS, granted p55 boards are relatively new and i went from 1.0 to 1.1, I tried fiddling with all kind of memory settings on BIOS, but I would still get the exact same error.
So finally, I tried it with only one memory stick in DIMM slot #1 and viola, everything works just fine. No BSoD, no instability, no crashes whatsoever. It didn't matter whether I was using OCZ or Corsair ram sticks; if I had only one stick installed, it'd be fine and quite rock-solid, albeit a bit slower than it's supposed to be since it has only 2g of ram and running it on single channel mode; it passed all of the stress test. But when one more stick is inserted, it'd spin out to hell.
** The MSI mobo manual cleary states that I should be populating DIMM slot #1 and #3 in that order before any other slots are populated, so that's the slots I've been using.
So what do you guys think my problem is?
1. Bad motherboard DIMM slot?
2. Bad CPU memory controller?
3. Bad PSU?
4. Bad BIOS setting somehow?
I would first try this:
Put in both sticks.
Set the BIOS to optimal defaults or similar. This should always be done before changing anything. Reboot and enter BIOS and set things the way you want. Then set the DRAM voltage to 1.65V - more important with 2 sticks than 1 - it's likely at 1.5V now.
If that doesn't work, try using slots 2 & 4 - that will confirm whether slot 3 is bad. Generally, either pair of slots should work.
If the above suggestions don't work,you can try testing the sticks on a different machine.If it ran without errors then,the processor's memory controller is faulty or the board has bad DIMM slot.You can find out which component is faulty by changing the CPU or testing your CPU on a different motherboard