This chart is good news for the folks who make decisions in offices around the world.
The Core i5-661—Intel’s highest-TDP Clarkdale-based CPU at 87W (the rest are 73W parts)—idles little more than 7W above the Core i5-750, despite its dual-die package. Amazingly, it’s 36W below the Lynnfield-based processor under load, though.
Core i5-661 uses less power at idle and under load than the Core 2 Duo E8500. It almost defies reality that the Core 2 Quad Q9400 would use such little power in comparison. But we’re actually using the Core 2 Quad Q9400S, rated for 65W (same as the 65W dual-core model). Now those load consumption numbers make a lot more sense, don’t they?
And while AMD’s Phenom II X4 965 Black Edition uses less power at idle, it’s a gross consumer under load (and this is the 125W version, too).
At the end of the day, the Core i5-661 is an absolute win in the power department for anyone already planning to use integrated graphics. Add discrete graphics, though, and that 45nm die largely goes to waste. Your outlook on Clarkdale’s power picture will largely depend on which side of that fence you’re standing.