Lapped core 2 duo IHS pics

[Fiber9]

Well, a Netburst-based 90nm 3.4GHz CPU is bound to be VERY HOT, and benefit from lapping much more than a C2D... You have to factor in the law of diminushing results. It is much easier to shave some degrees from a hot thing than from a cold one...
Miguel

A proper lapping job should produce better temperature results.
It's not so much dependent on the processor type, rather on the lapping job and the block used to cool the cpu.
The Noctua (heavy) is keen to flex the board.
Take a look at these results, extracted from the review Cooling-Masters web site made of the Apogee GT.