It looks like our Mac OS X backend doesn't properly handle processors that support hyperthreading without actually having hyperthreads enabled in hardware. Your processor has 4-core without HT but it's based on a processor with up to 8 cores and 16 threads. Our current code uses the latter and therefore wrongly assume you have HT cores, hence reporting 2 HT cores instead of 4 noHT cores.
I guess we would also be wrong if some cores or HT are disabled in software in Mac OS X. Anybody reading this from a Mac, could you send the output of these commands on your machine? sysctl -a | grep ^hw sysctl -a | grep ^machdep.cpu lstopo - Brice > > > Le 25/01/2018 à 07:14, Olivier Cessenat a écrit : >> Hello, >> >> I’m puzzled by the report from lstopo about the number of physical >> cores on an iMac with >> I5-7500. It is specified by Intel as a quad core processor and lstopo >> reports only 2 cores: >> lstopo >> << >> Machine (8192MB total) + NUMANode L#0 (P#0 8192MB) + L3 L#0 (6144KB) >> Core L#0 >> L2 L#0 (256KB) + L1d L#0 (32KB) + L1i L#0 (32KB) + PU L#0 (P#0) >> L2 L#1 (256KB) + L1d L#1 (32KB) + L1i L#1 (32KB) + PU L#1 (P#1) >> Core L#1 >> L2 L#2 (256KB) + L1d L#2 (32KB) + L1i L#2 (32KB) + PU L#2 (P#2) >> L2 L#3 (256KB) + L1d L#3 (32KB) + L1i L#3 (32KB) + PU L#3 (P#3) >> >> >> When running system_profiler SPHardwareDataType >> I obtain: >> << >> Hardware: >> >> Hardware Overview: >> >> Model Name: iMac >> Model Identifier: iMac18,3 >> Processor Name: Intel Core i5 >> Processor Speed: 3,4 GHz >> Number of Processors: 1 >> Total Number of Cores: 4 >> L2 Cache (per Core): 256 KB >> L3 Cache: 6 MB >> Memory: 8 GB >> Boot ROM Version: IM183.0151.B00 >> SMC Version (system): 2.41f1 >> Serial Number (system): DGKV7HJCJ1GN >> Hardware UUID: 3FDAD77B-F4E8-50AB-B0FF-AA5C41CA35FA >> >> >> >> Is there a trick ? >> >> Thanks for you help, >> >> Olivier Cessenat >> >> >> >> _______________________________________________ >> hwloc-users mailing list >> email@example.com >> https://lists.open-mpi.org/mailman/listinfo/hwloc-users >
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