I bought a Xeon Phi 7120p and need to upgrade the mobo from ASUS P9X79 PRO which does not support Xeon Phi (precisely, it does not feature "memory mapped I/O address ranges above 4GB" (there is a writeup about that here). I am a bit torn between two possibilities. Easier one is to just replace the mobo with ASUS P9X79-E WS, another one is to upgrade the whole gear and pass my current machine to someone else. That results in the questions: 1. The ASUS P9X79-E WS officially supports the Xeon Phi 3100 series, but people (e.g. here) use 5100 series as well. Is the 7120 somehow different, or it just more expensive and hence not explicitly mentioned? Will it work with that board? 2. If I am to buy new gear, I am thinking about AMD (dual 16-core Opterons or something similar). I understand Intel claiming compatibility with Xeon CPU's only (though I don't like this kind of monopolization through unclear compatibility). Is this risky? Someone had that one working? (I know AMD may not be a good idea for HPC, but I have code which scales pretty well and 2x16-core Opteron costs the same as 1x10-core Xeon...?) What should I look at? Or are Opterons just a no-go for computing? 3. If I go with Xeon CPU (single or dual), will all mobos work? How to check that? Intel is pretty reluctant at claiming compaitiblity and recommends to buy from complete computers OEMs. I don't want that. I want to pick my mobo and CPU and everything around. (I looked at ASUS ESC2000_G2 barebone, looks nice, that's what the people at openwall.info use, or perhaps just single CPU with ASUS ESC1000_G2). Some recommendations? I don't want rack, just server box, silent if possible (sits in my kitchen, behind the door when working). 4. I bought the passive-cooled variant, thinking that I will cool it just with some fan in the chassis... not so sure about that now... :/ These guys put dual 12kRPM fans but that will be noisy as hell. If I just buy e.g. 80mmx80mm fan with a bit more than required throughput (30cuft/min), and make a funnel to push the air through the cooler, will that work? Thanks for all information and input.