Try disabling memory remap with just 2 sticks of RAM - I don't think it has anything to do with the amount of memory detected by OS, but the best way to know for sure is to try disabling it. Instead of raising the FSB (you don't have the motherboard for that), try lowering it (just for testing). Say, set FSB to 266 and RAM to DDR2-800
. That should set the CPU to 2,5GHz, and RAM multiplier to 2:3. See how that works out. Set the PCI-E frequency manually to 100MHz. Test the system with 2 RAM modules. Report if that made any difference. I feel like we're following the right trail (I highly doubt that your power outlet has anything to do with restarts) and finding the stable settings is just a matter of trial and error - patience is the key
As for the voltages, they're in the acceptable marigins, on my system, +3.3V is slightly higher, but +5V and +12V are slightly lower.
The fact that you don't have memory strap setting doesn't matter, as long as you're able to change the memory frequency in BIOS. Theoretically, setting it to 800MHz in BIOS should result in exactly that, but it for some reason, Xeon is causing it to set the higher strap, resulting in higher frequency. Check your DRAM frequency in CPU-Z ("Memory" tab) with each Memory frequency setting in BIOS. Do all of the tests with just 2 memory modules, to rule out the northbridge strain from possible causes of reboots.
Whatever you do - don't leave RAM setting on Auto, it clearly doesn't help. When it's manually set to certain setting, at least you'll know what setting that is.
Out of curiosity - what HDD mode you've set in BIOS - IDE or AHCI? Try using IDE if you're currently using AHCI, but not the other way around Edited by Wojton - 12/28/14 at 2:44pm