4870 2d underclocking, 40w less idle

[Xcel]

So my computer draws 179w from the wall idle with the 4870 running at 500/900. Here's the thing if I lower it to 100/200 with amd gpu clock tool the idle power draw is 139w (I don't dare go lower, I started getting artefacts at 150mhz memory clock).

Why are the stock 2d clocks so high? Most of the time it just sits there in windows with 0% activity anyway

Without any fan speed adjustments
500/900 = 79c idle
100/200 = 56c idle

VRMs down from 91c to 56c.

So why can't the default 2d clocks be lower in ccc and its stupid 500/800 minimum limit. 40w less is very noticeble...

EDIT/ took a while for the temps to settle

0% GPU fan yet 1000rpm