Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: glennholt on January 09, 2016, 04:43:35 PM

Title: Mill running slow. DriverTest stuck at 5000 pulses/mn.
Post by: glennholt on January 09, 2016, 04:43:35 PM

I recently decided to consolidate my collection of computers into a VMWare ESXi VM server.  One of my victims was my old Dell 32-bit XP CNC box running mach3.  It's now virtualized, running with a PCI parallel port card that is passed directly through to the virtual machine.

It runs, but runs considerably slower than before.  Upon investiagation I found the following:

   1) It was not skipping steps.  I could accurately move the spindle around in MDI mode.
   2) It was running at a stable fraction of the previous speed.
   3) When I ran DriverTest it would always show 5000 pulses, regardless of kernel frequency.

I completely un-installed Mach3 (and pulse driver), and re-installed with no change.

So, is the issue likely the parallel port card or the virtual machine?   I've passed through other PCI devices with success.  Why 5000 PPM?  It seems like a huge clue, but one that escapes me...

Thanks for your help.

Title: Re: Mill running slow. DriverTest stuck at 5000 pulses/mn.
Post by: ger21 on January 09, 2016, 04:52:11 PM

Virtual Machine

Title: Re: Mill running slow. DriverTest stuck at 5000 pulses/mn.
Post by: glennholt on January 09, 2016, 05:05:32 PM

Any idea why 5000PPM is a relevant figure?  That's a 200uS latency -- I wonder if that's a time slice for some IO scheduler?