help with regular cpu usage spike

[altsao]

im running a VI thats reading data off a mouse through a VISA driver. i get these strange spikes in cpu usage which are regular at ~12-13 second intervals, which i haven't got a clue as to the cause.

any ideas??

[Michael_78]

Download sysinternals process explorer from Microsoft. It will give more details about the processusing CPU. You don't say its your labview app causing this spike so process explorer is a good place to start.

[altsao]

hi,

   thanks for the reply! although i will check with sysinternals, i am almost certain it is labview - it is also only this particular VI, which reads from an optical mouse through a VISA driver where i see this regular spiking in usage.

i should also say, this problem seemingly appeared out of nowhere - for months this VI had been running very smoothly, but then i reinstalled the VISA driver at some point, and since then, this spiking in cpu usage has occurred...

[Michael_78]

Possibly a Windows update? IT update? This could be an interaction between drivers / services. You could try running small sections of your code to identify the problem, and post your code if you have any other questions.
Good luck
Michael

[Yamaeda]

Antivirus scanning your visa drivers? Try turning it off for a while.

/Y

[Michael_78]

That was my thought too...

[altsao]

hi all,

   thanks for the suggestions. ive looked with sysinternals, and it appears to be a very minor increase in labview cpu usage - i closed all antivirus related processes, and the spike still continues, so it doesn't appear to be that...

ive attached the vi, in case its some stupid coding issue..

apologies for being so ignorant, but how would i go about checking if it's some issue caused by a windows update or whatnot..

[altsao]

ok, so i have made very little progress, but i have come to the conclusion that the issue is the optical mouse position, which is being read through a VISA driver, is issuing these regular system interrupts. it also appears to be something specific to the particular mouse i'm using, as when i switch to a different model of mouse, this problem is gone. 

anyone have any ideas why a particular mouse is causing such intensive system interrupts??