Hello,
I post in this topic because I have the same problem with a desktop PC. I istalled only winXP and mach3, but i have a lot of jitter in clock generation. Drivertest give me a result similar the result postet in the first post of Rasgueado. With 25KHz clock i have a shortest time of 36us, and longest time of 49 us. Testing mach3 with motors i have a very bad running.
Jitter in driverpulse result are not random, but they appear very regular.
PC sould be good for mach3 specific. It's a pentium dual 1600 MHz, with 1 GB of ram...
For comparison i run drivertest in other 2 desktop PC and in one laptop PC where i have mach3, and i have a very good result (only the laptop have very little jitter).
I try al the optimization suggest, but without improvement.
What can i do?