I had Mach3 Turn running quite well last weekend, but the motherboard on that machine fried. 

I got a new motherboard, processor, memory, hard drive, and got Windows XP Professional, just to make sure that the Windows XP Professional System Optimization Guide was 100% relevant.

I have gone through the Optimization Guide and did everything suggested, except for one thing.  On Step 9, when I tried to Update Driver on Computer to Standard PC, the DriverTest would not run.  Changing the driver back to Uniprocessor PC allows DriverTest to run to completion.  I had in Step 0 disabled ACPI in the BIOS Power Management Setup, so this shouldn't matter. 

When I connect up to the lathe, velocity values that previously were fine now result in motor stalling.  I used to get 1450, now I can't get 1000.  I have tried both 25000 and 35000 kernal speeds, and there doesn't seem to be a difference except what the motor tuning dialog reports as the possible maximum. 

When I slow the motor way down just to get it to work, the axes move, but I can hear a thudding on both axes that occurs roughly 3 times per second.  The frequency of the thudding noise does not change when I change the motor speed. 

I am using Version 1.90.017. 

Any advice on how to debug this would be appreciated.  Thanks. 

Just as a quick test please try running in Sherline mode..

Assuming I didn't need to reboot or restart, there is no difference. 

I think you need to restart... But I could be wrong...

I set the Sherline 1/2 pulse mode, applied, okayed, reset, shut down, and restarted Mach3.  There's doesn't appear to be any difference. 

Art should be back at it tomorrow I will tell him that we need to have his help.

Thanks.  I'll really appreciate the help! 

Hi Guys:

  I suspect your timing is not good. Run the drivertest.exe. Are you sure its showing a line with no hugh spikes of timeing variation??

Thnaks
ARt

I ran DriverTest and waited for a particularly bad spike, then grabbed the screen.  This is what I got (except that the original Timer Variations frame was gray, not pinkish):

It's usually quite flat with little variation, more like this:

As best I can tell, there's not much else going on: