D820 overheating issues
You may need to check your temperature shutdown temps in your bios if its shutting off at 60 degrees celsius, "the Intel D820 is made to run between 50 degrees celsius and 80" quoted from intel. My D820 runs fine at 66 degrees under full load on both CPU cores and that is after making some minor modifications to my case and getting a better CPU fan. I am loving my D820 it is a number cruncher that is for sure.
I have seen a lot of people liking the giant zalman cooling heatsink and fans. I am using a Coolermaster Hyper48 heatsink with a Vantec Tornado 80(up to 84CFM) MM fan with a variable controller on the front of my case. This Vantec fan from the stock one that came with the Hyper48 dropped my cpu temp more than 10 degrees C. With the Vanctec set on a low rpm it is at a very normal noise level and it keeps my cpu at around 66degrees celsius running the Prime 95 torture test on both cores. Another thing to note is that I have a plastic tube about 4-5 inches long and a diameter of 4 inches going from the side vent on my case to right above the CPU. Intel has a diagram on their website showing the proper usage of airflow for this CPU. I like the processor a lot now after I got over the hurdles.
The real way to test the stability of your CPU at its stock speed is to make sure your machine can run the Prime95 program for a minimum of 12 hours. You will have to have two seperate copies of Prime95 open at the same time after which you can tell each instance to run on a each of the cores. The torture test is what you want to run and if your temp is climbing over 75 degrees within the first few minutes then you know you have a problem with cooling. A lot of people will say that if your system can run Prime 95 the torture test for 24 hours without errors that your CPU is stable. After I added the Vantec Tornado 80mm fan and the proper venting I was able to run Prime95 on both of my cores at around 66 Degrees Celsius on a low RPM setting. I could push the temp down more if i wanted to listen the whining of the fan, and it is tolerable if you like the sound of a server.
In the future I will try a few different cooling solutions like the Zalman and then eventually water cooling to see if i can eliminate noise.
The Vantec Tornado with a variable controller was a cheap solution for cooling my system after i had already bought a heatsink and fan combo and wasn't able to return it.
I had a lot of fun building my system and suping it up to run better under a full load.
You can read more about my experience and other questions i have at the following link with the Intel D820 and heating issues.
http://forums.techpowerup.com/showthread.php?p=67210#post67210