topic Hi Tobias: in Analyzers

How to choose the (correct) CPU for profiling?

Toby — Tue, 18 Mar 2014 14:58:53 GMT

I'm quite new to vTune profileing so I'm guessing this is a simple question: When choosing the analysis type, I can see for the event details: "Event configured for CPU: Intel(R) Xeon(R) E5 processor". But the processor for the profiled hardware is Intel Core i7-3930K. Why does it say that it is a Xeon processor and is the test metrics collected inaccurate due to this?

I reckon that vTune is able to read the processor type on the computer being tuned. I guess one answer could be that that i7 desktop architecture is based on the server Xeon architecture so that the profiler sees no difference?

Hi Tobias:

David_A_Intel1 — Tue, 18 Mar 2014 15:58:44 GMT

Hi Tobias:

Yes, there were some processors released as high performance desktop chips that are based on the server processors. Yours appears to be a Sandy Bridge-E part.

Where do you see "Event configured for CPU: Intel(R) Xeon(R) E5 processor" in the display? Is that in the event reference documentation?

Ok, I see. Thanks. But that

Toby — Tue, 18 Mar 2014 20:27:33 GMT

Ok, I see. Thanks. But that this mean that the processor is actually not a Core i7-3930K brand but rather a Xeon E5-16xx as the Wikipedia Sandy Bridge-E documentation (in overview section) seem to hint? The Wikipedia documentation is a bit confusing too me also since it says it is 8 core based though this Core i7-3930K processor is 6 core only. Btw: Windows 7 states it is a Core i7-3930K processor and not a Xeon.

I would be interested to read more Intel based documentation on this if possible beside this overview and this which seems to be a bit more high level documentation of the i7 processor family. Neither of these gives any hint of a Xeon based processor as far as I can see. It would be really good to know for sure what the deal is on this matter.

As for answering your question: yes: I beleive it it is the event reference documentation for when choosing the alsysis type. I provide a snapshot picture just in case:

Hi Tobias:

David_A_Intel1 — Tue, 18 Mar 2014 20:35:11 GMT

Hi Tobias:

I'm not really versed in identifying Intel processors. I work with the VTune Amplifier XE. I can tell you that VTune Amplifier XE will either be able to identify the process or it won't. If it does, it will collect the correct counters. If it can't identify the processor, it won't let you collect any counters (other than Advanced Hotspots, which just collects CPU_CLK_UNHALTED and INST_RETIRED). BTW, which version of VTune Amplifier XE are you using? You should always use the latest release. Update 16 was released last Friday.

If you are running Windows, you can download cpu-z from www.cpuid.com and it will tell you exactly what processor, including the codename and all sorts of other details.

Ok. Thanks for the tip. I'll

Toby — Tue, 18 Mar 2014 20:48:26 GMT

Ok. Thanks for the tip. I'll update vTune from v15 to v16 then.

I actually was using zpu-z already but this tool does not either give any hint of a Xeon based processor. Oh well, I guess I must drop it. Thanks anyway for your feedback.

I think I found some detailed

Toby — Thu, 20 Mar 2014 10:05:08 GMT

I think I found some detailed documentation on what I was looking for regarding more throrough Intel documentation (in case someone else is interested): http://software.intel.com/sites/products/collateral/hpc/vtune/performance_analysis_guide.pdf

Also, found this review from 2011 also mentions that "Sandy Bridge E is really a die harvested Sandy Bridge EP, Intel's next generation Xeon part".

>>>I think I found some

Bernard — Thu, 20 Mar 2014 10:50:06 GMT

>>>I think I found some detailed documentation on what I was looking for regarding more throrough Intel documentation (in case someone else is interested): http://software.intel.com/sites/products/collateral/hpc/vtune/performance_analysis_guide.pdf>>>

Btw, great document.