- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Hi,
I am new to VTune and was interested in knowing how does VTune collect the performance counter data? Does vTune capture counters while the OS code is executing? Are the counters being updated in user space or in kernel space?
Thanks.
Link Copied
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
VTune uses hardware PMU to measure. The general formula is -
MFLOPS Formula = A-specific-event counters / 1,000,000 / Elapsed Time
Elapsed time = CPU_CLK_UNHALTED.THREAD / Processor-Frequency / Number-of-Cores
Please see this blog to know examples in detail.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Hello,
It is worth also to look at https://software.intel.com/en-us/node/544067 to understand the sampling collection method that VTune use for hardware (driver) based collections.
BTW - what particular HPC data are you interested in?
Thanks & Regards, Dmitry
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
And, actually, there are two different collection mechanisms: one is software-based and one is hardware-based. It depends on the analysis type you select.
So, again, what specifically are you asking about?
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Thanks for the reply guys. I am dealing with HPC for branches, cache misses and memory uops.

- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page