I read on newegg that the 9211 overheated often for someone but I never had any problems while benching it. The 9260 heatsink gets about as hot as ddr3 with no fan but it's never had any issues, it gets a little air that's blowing out of a hot rad but that's about it.

To answer your question it seems close to the size of many small blocks I've seen but I'm not certain. I can't imagine needing it possibly in a server environment but then you're going to have some good san ace's blowing on it and the AC set to 'antarctica'.