[snuxoll]

The Xeon E3-1270's in my R210 II's are 80W TDP, the Xeon E5-2450L's I have loaded in my R320 and R420 are 70W - guess which makes more noise? The 2450L's, of course!

TDP is a guideline for cooling, it says nothing about noise, or even power draw. The former is a factor of the cooling system you have paired, the latter can be completely arbitrary as long as the chip can average itself out to the rated heat dissipation (which is what the TDP measures).

If you want a quiet home server, get a tower, my ThinkServer TD340 was hella quiet even with two Sandy Bridge-EN chips installed. Beyond that it doesn't really matter, hell, swap out the CPU cooler and case fans with Noctua ones to go the extra mile.