For testing power consumption we took our test system and plugged it into a Seasonic Power Angel. For idle numbers we allowed the system to idle on the desktop for 5 minutes and took the reading. For load numbers we measured the peak wattage used by the system while running through 3DMark 2006.
The shrink to 80nm helps out here, the X1950 Pro uses 50w less power than the 256MB X1900XT under load. ATI is now competing very closely with NVIDIA in performance per Watt, with 11W separating the 7900 GS and X1950 Pro when the system is really cranking.
The power savings really add up here as a pair of X1950 Pro’s actually use less power than a single X1900XTX under load! The 7900 GT pair still uses 10w less than the X1950’s under load while at idle the latter uses 6w less.