July 7th 2009
Some very preliminary performance information, more will be added later.

Ham Radio Deluxe
From the Tools menu select Program Options, Comms and use a longer refresh interval 

Satellite Tracking
From the Tools menu select Options, Image, and select Default quality.
In Radio Options select Radio Connection then select Normal update speed.

Graphics
In both Rotator and SatTrack I can reduce the CPU spikes when redrawing

General
Disable anti-virus / network monitoring of traffic on the HRD port (usually 7809 - Tools, IP Server)
Disable anti-virus / network monitoring of traffic on serial ports

If CPU usage is high use the Task Manager in Windows to see which processes are using the CPU.