Yesterday I have setup a kfreebsd-amd64 (ie GNU/kFreeBSD on an amd64 CPU) build daemon. Its name is shockley.aurel32.net (all my machines are named related to electronics), and it has Sempron 2600+ CPU.
As you can see on the photo, it is still missing a decent case. There are actually two machines on the the photo, the motherboard in the case is maxwell's one (one of the kfreebsd-i386 build daemon), while the one on the top front is shockley's one. That's a bit strange, but the amd64 motherboard needs a power supply with a P4 connector, while the other one only needs a small power supply.