Hi all!
I have 85% of GPU utilisation on first 8800 GTS 512 and about 83-84% on second 8800 GTS 512, W7x64, drivers 258.96.
In F@H I have 99% of of GPU utilisation on both cards at every task.
Is it normal for GPUGRID?
Both cards with my custom cooling profile in card's BIOS'es, so temperature rise is not an issue for me.
Do you plane to rise GPU's utilisation in GPUGRID?
I want 99% of utilisation. :o))

GPU utilization is something that the developers continuously work on.
The present utilization for most tasks is very high.

Other GPU projects have higher GPU utilization because they are running more simple tasks, with less CPU requirement.

To get some perspective, you might want to open Boinc Manager, goto Tasks, click on a CPU task and Properties. Look at the difference between CPU Time and Elapsed Time. The difference (overhead if you like) is usually about 15%.