Used Xeon X5690 Failing Prime95

[hyrule571]

Hello everyone. I need some help with a CPU I've just acquired. Desktop not overclocked whatsoever.

Motherboard: EVGA X58 SLI3
CPU: Xeon X5690
RAM: 3 x 2GB of Patriot Sector 7 @ 1333MHz (rated for 1600MHz)
GFX: EVGA GeForce GTX 780 Ti
Storage: 512GB Crucial MX100, 2x250GB WDs in RAID0
PSU: Rosewill HIVE-650W
Sound Card: ASUS Xonar D1
Case: DIYPC Alpha-GT3

Desktop used to be equipped with an i7-950 at stock clocks. Took out i7-950, and placed Xeon X5690 in socket carefully. Applied AS5 thermal paste. Finished the installation carefully, and made sure the heat sink assembly is tightly secured. Next, I cleared CMOS and configured BIOS for more compatibility. I left everything stock in regards to clock rates and voltages. Desktop reboots and identifies the new processor successfully, and Windows 7 64-bit likes the new processor too.

I downloaded Prime95 to ensure that the processor is okay. I started with a regular "Blend" test. The very first time I ran this test on this desktop, I got...

[Mon Sep 05 19:25:25 2016]
Self-test 24K passed!
Self-test 960K passed!
Self-test 24K passed!
Self-test 1120K passed!
Self-test 1120K passed!
Self-test 1120K passed!
Self-test 1120K passed!
Self-test 1120K passed!
Self-test 1120K passed!
Self-test 1120K passed!
Self-test 1120K passed!
Self-test 1120K passed!
Self-test 1120K passed!
[Mon Sep 05 19:30:41 2016]
FATAL ERROR: Rounding was 0.5, expected less than 0.4
Hardware failure detected, consult stress.txt file.
Self-test 24K passed!
FATAL ERROR: Rounding was 0.5, expected less than 0.4
Hardware failure detected, consult stress.txt file.
Self-test 32K passed!
Self-test 32K passed!
Self-test 32K passed!
Self-test 32K passed!
Self-test 32K passed!
Self-test 32K passed!
Self-test 32K passed!
Self-test 32K passed!
Self-test 32K passed!
Self-test 32K passed!

Afterwards, I ran a series of tests including the regular large FFTs test, and the regular small FFTs test for two hours each. No errors at all. Next, I burned an .iso of MemTest86 v4.3.7 and ran it for 21 hours. The following picture is the final result...

At this point I had believed my RAM was not the point of failure. I turned back to Prime95. I configured Prime95 with a custom setup (8K-4096K, "Run FFTs in-place" Off, 4816MB RAM use, and 30 minutes for each FFT size). I came back to my desktop to see the following...

I clicked "Close program" and the computer froze. So, I hit the physical reset button on my desktop. Afterwards, I went into Prime95's logs and saw the following...

[Wed Sep 07 08:08:57 2016]
Self-test 1120K passed!
Self-test 1120K passed!
Self-test 1120K passed!
Self-test 1120K passed!
Self-test 1120K passed!
Self-test 1120K passed!
Self-test 1120K passed!
Self-test 1120K passed!
FATAL ERROR: Rounding was 0.5, expected less than 0.4
Hardware failure detected, consult stress.txt file.
FATAL ERROR: Rounding was 0.5, expected less than 0.4
Hardware failure detected, consult stress.txt file.
FATAL ERROR: Rounding was 0.5, expected less than 0.4
Hardware failure detected, consult stress.txt file.
FATAL ERROR: Rounding was 0.5, expected less than 0.4
Hardware failure detected, consult stress.txt file.

There is no more text recorded. Take into consideration the maximum recorded temperatures in the photo I took. They're not that high. I ran another test, and Prime95 crashed again. Temperatures weren't even that hot this time around and lower than what's in the picture above. Prime95 settings were 24K-1120K, 4096MB RAM use, "Run FFTs in-place" Off, and 20 minutes for each FFT size.

[Thu Sep 08 13:39:52 2016]
Self-test 336K passed!
Self-test 336K passed!
Self-test 336K passed!
Self-test 336K passed!
Self-test 336K passed!
Self-test 336K passed!
Self-test 336K passed!
Self-test 336K passed!
Self-test 336K passed!
Self-test 336K passed!
Self-test 336K passed!
FATAL ERROR: Rounding was 0.5, expected less than 0.4
Hardware failure detected, consult stress.txt file.
[Thu Sep 08 13:47:15 2016]
FATAL ERROR: Rounding was 0.5, expected less than 0.4
Hardware failure detected, consult stress.txt file.
[Thu Sep 08 14:00:47 2016]
Self-test 32K passed!
Self-test 32K passed!

That's all. No more text was recorded. Ran Prime95 another time, but this time with the regular small FFTs test for 6 hours and 10 minutes. No errors whatsoever, but temperatures reached higher than ever. I bumped VCore from Auto to 1.25V, and VTT from Auto to +25mV. Still, Prime95 crashes.

Can somebody please give me a hand here?

 

[hyrule571]

Bump.