With all four RAM sticks in, the RAM Stress Test causes a restart, which often spirals into a series of immediate restarts that occur even before POSTing. But when I put only three sticks in, the machine passes the stress test without a crash. Thinking that one of the sticks might be bad, I swapped them around and there was no apparent difference. It didn't matter what sticks were in, as long as no more than three sticks were in, it would run fine. I thought that the fourth RAM slot on the Motherboard might be bad, since I always filled them up in order (slots 1-3, for 3 sticks). So I moved the third stick to the fourth slot (1,2,4 - for 3 sticks), and ran the test again. It passed. So I can conclude none of the sticks are bad, and all four slots are working, right? But my machine can't run stably with all four in. What could this be? A BIOS setting, a motherboard fault, and power issue? Man, I'm running out of ideas!
Intel Core i7 3770 3.4 GHz CPU
** BIOS F9 ** Gigabyte GA-Z77-DS3H Motherboard
16GB Corsair DDR3 1600 MHz RAM, 4x4GB
OCZ Vertex 4 512GB Solid State Drive
Corsair Professional Series 650W Modular Power Supply
I ran memtest86+ on each stick alone for 3 successful passes each with no errors (about 1.5 hours per stick). Since each one passed that amount of testing, and since that my machine will crash within 10 mins when all four are in, I'm assuming it's not the ram modules themselves. It must either be my motherboard, or related to power settings in the bios.
After running memtest86+ on each stick, I put in all four and ran it for 5 hours and 3 successful passes. At the end of the test I realized that my RAM was configured to 1333MHz when they should be 1600MHz. So I went into the BIOS and changed the Memory Multiplier to 16.00 and confirmed that the timings on each strip were correct (9-9-9-24), and that the SDRAM voltage settings was set to 1.5v.
Now, my ram was all set properly. So I booted into OS 10.8.2 ML and ran MemoryTester Stress Test and within 10 mins I had another crash. When my system rebooted it continued to crash because the CPU fan couldn't start up...
I wen't back into the BIOS and loaded the Optimized Settings, which set the RAM back to 1333MHz. I booted into ML again, ran the Stress Test, and bam. Another crash within minutes...
Anyone out there that can help!? I'm about to RMA everything...