Just got my X4 620 from SCAN today, running naked
CPU (AMD Athlon X4 620) -> £72.5
Motherboard (GA-MA78GM-UD2H)-> £30
PSU (OCZ 400W)-> £30
OCZ DDR2-1000 2x2G -> £40
Harddrive -> Spare Seagate 7200.9 drive lying around
Total Cost -> £172.5!
Undervolted from 1.4V default to 1.1V, prime95 @ 98.9W from the wall
This is getting so close to beating my beloved T8400 laptop @ 43W in terms of power/watt, as well as twice the processing power at much lower than half the hardware cost.
The stock AMD heatsink is doing an amazing job at 38'C full load with the included paste. Probably don't even need to bother with giving it some AS5. And it is extremely quiet even without the case. Most importantly it only took me 5 minutes to assemble
Haven't been more excited going back to AMD.