topic Memory bandwidth measurement in Software Archive

Memory bandwidth measurement

Isaias_Z_ — Thu, 15 Aug 2013 18:48:44 GMT

I want to know the rate of memory bandwidth, in GNU/Linux, but i can't find some way.

There are tools that read Memory bandwidth, but i believe they read the factory value no the current rate in time execution.

An other doubt is, when we deactivate the caché memory(setting bit 30 in CR0 register), it get slow performance(other topic), but this sluggish performance is for lack of caché memory o the decrease is caused by decreasing rate of 'memory bandwidth' in the main memory?

Thanks

Intel's PCM tool and Intel's

McCalpinJohn — Fri, 16 Aug 2013 14:17:25 GMT

Intel's PCM tool and Intel's VTune package can read the memory traffic counters and compute the memory bandwidth on many (most?) recent Intel-based systems, especially under Linux. (I don't follow what the current capabilities are under Windows.) In the Linux world, newer kernels (e.g. 3.7 and above?) can read the memory traffic counters on recent Intel processors.
I recommend a Google search using the terms: memory bandwidth site:intel.com

This functionality has been back-ported to RHEL 6.4, and I have posted an example of how to use the Linux "perf" facility to read these counters in another topic in this forum (http://software.intel.com/en-us/forums/topic/413912 entitled "ACT_COUNT littile than PRE_COUNT.PAGE_MISS").

Thanks John D. McCalpin I

Isaias_Z_ — Sat, 17 Aug 2013 00:19:48 GMT

Thanks John D. McCalpin I will prove it.

Hi Isaias,

Sumedh_N_Intel — Wed, 21 Aug 2013 16:49:21 GMT

Hi Isaias,

You may also find the following tutorial and article helpfull. Both of these focus on using Intel VTune Amplifier XE for computing memory bandwidth of your application.

http://software.intel.com/en-us/videos/intel-vtune-amplifier-xe-video-tutorial-4-running-memory-bandwidth-and-custom-analysis

http://software.intel.com/en-us/articles/optimization-and-performance-tuning-for-intel-xeon-phi-coprocessors-part-2-understanding