This setup seems to work well and was easy!
- picked it up at Fry's B&M
Re-purposed a 1TB Sata fullsize I had sitting around.
I installed W7 in order to prove the hardware (I ran HCI memtest and LinX - (linpack) each for ~12 hours) while W7 was installed, I updated the BIOS and disabled unnecessary BIOS devices. I'm sure there are Linux version of stress testing packages but I am more familiar with W7 stress testing, so for me it was quicker/easier to set up. I also pulled the CPU heatsink and replaced the thermal paste with Arctic Silver 5, during the tests (case top off) the passively cooled CPU cores never got above 52C! (79F ambient room). (Currently with case top off, it just sits at ~50C! ambient 77F - With case on it runs ~58C).
After it passed all the hardware stress tests I initially tried 64bit pfSense but I didn't get past the video issues - it looked like video wouldn't scroll during install - one line overlayed the next while not completely erasing the previous line, not sure if the install could have gotten past that or not. I wasn't that patient so I aborted and installed 32bit pfSense-memstick-2.0.1 (i386 from a USB flashdrive). There were a few video issues at install, ie: white squares where characters should have been, and blank lines on some of the graphics, hit the F10 to refresh and got thru it easily enough.
This is for my home network so my configuration is not very complex at all - I came from a DD-WRT, so there was a bit of a learning curve to get pfSense configured. I played with it a short time on a private network and got familiar with the basics. I replaced the DD-WRT router with pfSense and it's been up working for all of 1 day!
I plan to upgrade the the HDD to an SSD soon and swap to 64bit when FreeBSD supports the video better.
EDIT - Changed the temp info, originally the case top was off, when I put it on the CPU temps rose to ~58C (ambient was 79F), which is still I believe, well within Intel spec's.
EDIT #2 - Kill A Watt says 23 watts.