Quote: Originally Posted by simwells /img/forum/go_quote.gif Well what is the easiest way to work out if a heatsink would be adequate? The thermal resistance? If you can find some old PCs, the heatsink for probably anything Pentium or later would be sufficient. In my second p2p build I used one cpu heatsink for both MOSFETS. Quote: Originally Posted by simwells /img/forum/go_quote.gif I mean I'm looking at heatsinks that fan outwards and so the footprint that it actually sits on is smaller than the fanned out dimensions. Do you have any idea of what you would consider to be roughly the minimum size to be then? My 2nd and 3rd builds used this case: small aluminum project case 113x70x25 (Similar cases can be found on eBay at similar prices, but with free shipping.) It was pretty tight, but manageable if you do careful planning. A month or so ago in the for sale forum someone sold a Starving student that's really small, barely any space left after tube sockets and heatsinks. The pictures of my 2nd & 3rd p2p build can be found here: 2nd p2p build with CPU heatsink 3rd SSMH, with corrected wiring mentioned a few posts down Good luck!