> turned on. I asked NI about this and they say that they know LabVIEW
> doesn't work with Hypertheading!! For some reason they don't think it
> is important enough to mention on their web site.
Just to be clear, "doesn't work" may imply that a LV program will get
the wrong answer. This is not the case. A LV diagram will run on any
Pentium compatible processor from 486 to Xeon and get the same results.
The differences you will see will be in performance.
The combination of the Windows thread libraries and the hyperthreaded
architecture seem to throw a few curves to applications running on them.
In particular, the caches on these chips seem prone to being flushed
quite often and quite easily compared to a true multiCPU computer. The
strange things is that the behavior is somewhat different on linux.
After much investigation, we think we have cornered the problem,
reported it to MS and intel, and developed a solution. The upcoming
version of LV should show better performance on hyperthreaded computers
running Windows, but again, the current version, even version 5.0 should
give correct results, correct answers.
From our investigation, it also seems that the MS thread libraries
could be tweaked to give this boost to other multithreaded applications.
We don't have any word yet, but it is worth retesting as new MS
patches become available.
Greg McKaskle
