Just a ballpark, but the X7DCA-L with 12GB (!) of Reg ECC DDR2, a HD4850 and 2 E5420's (C0) draws below 180W crunching - imagine some E0 L5420's, a PCI GFX, 2 sticks of ram instead of 6 and less/no HDDs and you'd be looking at a VERY low power cruncher, maybe 140-150W loaded. Kicks out around 22-23k/d too so energy efficiency is actually better than a Sossaman. But the parts usually aren't cheap... Unless you can grab mobo and CPUs used for cheap.