Profile VIs

[Mikael_Garcia]

When I profile my main VI the total time for the execution does not correspond to the sum of the VI Time column (the total time is about 30s). Why is that? In my program I use SQL functions to write data to a database and I am trying to improve the total performance. I did a quick check and put toghether three subVIs (massive for-loops) into a main VI. This time the total execution time is the sum of the VI time column after the profiling (30 seconds total execution time again). Any ideas why I might see a discreapancy in my real program? Thanks in advance. /Mikael

[LucaP.]

Hi Mikael

Check this two links for important informations concerning the profile VI:
http://digital.ni.com/public.nsf/websearch/6DD24A34303735EF86256B06000B533F
http://digital.ni.com/public.nsf/3efedde4322fef19862567740067f3cc/862567530005f09c862566ef005ed94f

Hope this helps.

Luca

[Mikael_Garcia]

Hi Luca,
Thanks for your quick reply. I missed those two publications. But when I coded my test program with the three subVIs I started out with just delays... I then figured that the delay is not taken into account in the profile funtion (very confusing indeed). That is why I used massive for-loops. But my problem is not that the time listed is more than what I clock (the problem discussed in the links). My problem is the opposite. I attached a picture showing the profile from yet another test I performed. I clock this test VI (Test2.vi) to about 7.8 seconds. But I don't understand where those 7.8 seconds are spent. The total time according to the profile should be 4.875 seconds in this example. I wonder what is going on? Do you have any more
ideas? /Mikael

[Randy_H]

Mikael,

The SQL toolkit is using a lot of native code. This code takes a while to run, but the profiler does not have timing control over it. That is probably where the timing differences come from.

Plus, there is always a little overhead in the profiler anyway, but I agree that it is not 3 seconds.

Randy Hoskin
Applications Engineer
Nationsl Instruments
http://www.ni.com/ask