How can I run two independant LabView applications from the same computer, without taking a performance hit?

[Arun Madangarli]

I have two identical, but independant test stations, both feeding data back to a Data Acquisition Computer running LabView 6.1. Everything is duplicated at the computer as well, with two E-series multifunction I/O cards (one for each test station) and two instances of the same LabView program for acquiring and analysing the data. The DAQ computer has a Celeron processor w/ 850Mhz clock and 512MB memory, and is running on Windows NT.

I have noticed that when I run both the applications simultaneously, I take a substantial performance hit in terms of processing speed (as opposed to running just one program). Why does this happen and how can I prevent it? (In t
his particular case, it may be possible to combine both the tests into one program since they are identical, but independant, simultaneous control of two different LabView programs is a concept I need to prove out).

Thanks in advance for any tips, hints and spoon feedings (!)....

[shoneill]

Depending on your application, you may or may not be able to improve things.

Firstly, each task requires CPU time, so a certain performance difference is guaranteed. Making sure you have a "wait until ms" in every while loop helps in all but the most CPU intensive programs.

Secondly, if you are
1) streaming data to disk
2) Acquiring lots of data over the PCI bus
3) Sending lots of data o ver the network

you can have bottlenecks elsewhere than in your program (limited Disk, PCI or Network bandwidth).

Avoid also displaying data which doesn`t need to be displayed. An array indicator which only shows one element still needs a lot of processing time if the array itself is large.... Best is to set the indicator invisible if this is the case.

I think
it would be best if you could give some more information about the amount of data being acquired, processed and sent. Then maybe it will be more obvious where you can optimise things. If you are running W2000, try activating the task manager while the program(s) are sunning to see where the bottleneck is.

Shane