This link gives some info on the timers. There are other options for reading higher precision clocks, but for message timers, this is pretty good way to go for Windows. Note that the API doesn't guarantee that it will provide one ms resolution, but I've never seen a computer that had a value other than one.
http://msdn.microsoft.com/en-us/libr...(v=vs.85).aspx
Marshal was measuring the time at the robot. His first post has attached code, along with a much more interesting dataset from an earlier version of the DS when more UI stuff was causing overhead and lots of jitter.
Will C++ programs have the same resolution? It depends on how they are written. The LV editor and runtime are C/C++, so they call the multimedia API and increase the timer resolution. If they didn't do that, I think the modern Win32 event stuff would have a resolution of more like 16ms. I can't remember for sure what that number is, but the easiest way to measure it is to write a loop that measures the current time, sleeps for a small amount, and checks the time on wakeup. You can then compare the requested sleep amount to the actual time the thread slept.
I've attached images of some similar tests, each run on my VM'd windows 7 that is actually running on my mac. The top chart is a regular while loop with a sleep ms multiple, which attempts to preserve phase, but doesn't try to catch up. The bottom chart shows the same code, but with a timed loop, also set to discard misses, but retain phase. The timed loop in LV implements its own scheduler based on a high priority thread. It improves things a bit on windows, but really shows its stuff on RT OSes. Note that the first point is typically low because the loop is aligning to the clock phase. The tests were also run with standard priority.
As for the other articles you attached. I think that info is most appropriate for threads that do not yield due to I/O. If you have several computational threads maxing out the cpu(s), and you also have the timing threads running.
Due to technical difficulties with the attachments button, I'll attach loaded images in a followup post.
Greg McKaskle