Thanks Ben for providing BIOS info. I see following : [BIOS::Advanced::Processor Configuration] L1 Prefetcher=Enabled ;Options: Disabled=00: Enabled=01 L2 Prefetcher=Enabled ;Options: Disabled=00: Enabled=01 So this might be one way to disable/enable the hardware perfecting (?). -Pramod On 06 Jul 2016, at 19:48, Kumbhar Pramod Shivaji <[email protected]<mailto:[email protected]>> wrote: Regarding knl hardware prefetcher, I read something like “hardware prefetchers can be disabled within the BIOS menus at boot time or using BIOS tools, specific to your machine”. I am not sure if this is true (for current knl nodes / BIOS), people who can look at BIOS settings or intel folks can provide more information regarding this. “software” or “compiler” prefetching is enabled by default with -O2 which could be disabled by -opt-prefetch=0 / -no-opt-prefetch or “pragma noprefetch”. I see prefetch instructions like prefetcht0, prefetchnt1 or _mm_prefetch intrinsics but haven’t come across anything to disable it like data stream control register you mentioned for power8 (expect for some<https://software.intel.com/en-us/articles/disclosure-of-hw-prefetcher-control-on-some-intel-processors> other microarchitectures). -Pramod On 06 Jul 2016, at 08:29, Delalondre Fabien Jonathan <[email protected]<mailto:[email protected]>> wrote: Last time i asked intel it was not possible to disable hardware prefetcher. I believe you can pass hints to indicate you want to disable software prefetcher but i dont remember whether they were just hints (that can be ignored) or not. Best, Fabien On 6 juil. 2016, at 00:05, Chunduri, Sudheer <[email protected]<mailto:[email protected]>> wrote: Hi, Is there a way to disable HW prefetch on KNL? For ex, on POWER8, user can use intrinsics such as __prefetch_set_dscr_register(40) to disable hw prefetch Or user can use a compiler flag to control prefetch. Is there a similar method available for KNL? regards Sudheer _______________________________________________ Intel-nda mailing list [email protected]<mailto:[email protected]> https://lists.jlse.anl.gov/mailman/listinfo/intel-nda _______________________________________________ Intel-nda mailing list [email protected]<mailto:[email protected]> https://lists.jlse.anl.gov/mailman/listinfo/intel-nda _______________________________________________ Intel-nda mailing list [email protected]<mailto:[email protected]> https://lists.jlse.anl.gov/mailman/listinfo/intel-nda