ProductReviews: So we know that the new 80GB version of the Sony PS3 was upgraded with a larger hard drive. We did not know however that it would be more energy efficient than the 40GB version.
It seems that the Core does use less energy than the smaller hard drive version. A user from Slickdeals forum connected his 80GB PlayStation 3 up to a Kill-a-watt and was shocked at his findings.
The 80GB PS3 used 130 watts of power while playing MGS4, whereas the 40GB version used 155.2 watts of power. That’s not all, on idle the 80GB version uses 111.9 watts, whereas the 40GB model used 125.8 watts when idle on the XMB.
There are many theories as to why this is; the most popular is that Sony is now using the 65nm RSX chips.