Account for run-to-run variation in bandwidth with vtunes

[Pradeep_R_]

Hi all,

Does vtunes account for run-to-run variation in bandwidth when doing "bandwidth analysis"? If so, how does it? If not, how can we as users do it?

Thanks,

Pradeep.

[Thomas_W_Intel]

I'll move this thread to the VTune forum.

[Peter_W_Intel]

I'm not sure if I understand your question exactly...

Usually VTune Amplifier XE will create a default "vtune" group or you can specify any group for vtune drivers access, by using "./insmod -g vtune". Your account should be in "vtune" group then can use bandwidth analysis (will access device drivers)

However, latest product now sets "666" for file access permission, it means - all users can do bandwidth analysis.

Try: "amplxe-cl -c bandwidth -d 20 - application"

Note that bandwidth analysis is supported since SandyBridge processor, latest product is 2015 U4.

[Pradeep_R_]

Oh, I think you misunderstood my question - apologies if the wording wasn't clear!

I am not having any trouble running the bandwidth analysis through the command line, or the GUI - they work like a charm!

My problem was that when doing bandwidth analysis and re-running the same executable with the same arguments multiple times, I get considerably different bandwidth profiles. I am assuming that this is a property of the application but I was wondering if there is some way in which vtunes can account for run-to-run variation in bandwidth of the same executable on the same system and give a dependable graph plotting bandwidth over time.

Thanks,

Pradeep.

[Dmitry_P_Intel1]

Hello Pradeep,

What is the difference in run-to-run case that you see on timeline?

We don't have anything specific to account run-to-run variation.. How this can work from your point of view?

Thanks & Regards, Dmitry

[Pradeep_R_]

Thanks Dmitry. Maybe you can have an option in vtunes bandwidth exploration to take N measurements and compute some sort of average before displaying the bandwidth results?

Pradeep.