So here are the screenies.

i7 860 @ 4GHz


i7 920 @ 4GHz


Well different WUs to Bob so the duration will be different but you get the idea.

The 860 @ 4GHz has a runtime of 99:51:44 for 24 WUs or 4:09:39 per WU on avg
The 920 @ 4GHz has a runtime of 96:09:33 for 24 WUs or 4:00:24 per WU on avg.

This is a 9min difference per WU or 4% per WU

So not sure what I need to change except for the memory settings. Any ideas as I'll set these to run again if required.