Benchmark Results show too many CPUs

Questions and Answers : Macintosh : Benchmark Results show too many CPUs

Author	Message
Charles Michael Fulton Send message Joined: 13 Nov 09 Posts: 8 Credit: 170,900 RAC: 499	Message 1119601 - Posted: 21 Jun 2011, 5:04:43 UTC
	I have a 2009 Mac Pro Quad Core 2.66 ghz, which I recently purchased. When running the CPU benchmarks, BOINC identifies "8" as the number of CPUs. Not a huge deal, but I think that BOINC downloads 8 tasks and attempts to do them all at once. This results, I think, in a less-than-optimum workload for my Quad Core Mac. If it would just download 4 at a time, I think it would finish the tasks much quicker. Has anyone else experienced this problem? Is there anyway to adjust BOINC so that it sees 4 cores instead of 8?
	ID: 1119601 ·

pixzy Send message Joined: 7 Jun 99 Posts: 103 Credit: 2,910,837 RAC: 929	Message 1119649 - Posted: 21 Jun 2011, 9:47:22 UTC - in response to Message 1119601.
	There is a place in preferences where you can set how many cores Boinc should use. ____________
	ID: 1119649 ·

Gundolf Jahn Send message Joined: 19 Sep 00 Posts: 3078 Credit: 341,914 RAC: 96	Message 1119652 - Posted: 21 Jun 2011, 10:38:43 UTC - in response to Message 1119601.
	You probably have turned on hyperthreading. So, BOINC correctly sees eight CPUs (four real and four virtual ones). You can either turn hyperthreading off or, as pixzy suggested, go to your Computing preferences and set "On multiprocessors, use at most 50% of the processors". Gruß, Gundolf
	ID: 1119652 ·

Volunteer tester Send message Joined: 9 Apr 02 Posts: 11987 Credit: 18,248,897 RAC: 57,663	Message 1120416 - Posted: 23 Jun 2011, 14:34:19 UTC - in response to Message 1119601.
	According to Intel, your Xeon W3520 is a quad core CPU with Intel HyperThreading Technology. HyperThreading takes each physical core and makes it appear as two logical cores to get more efficient use out of the processor registers. So in fact your 4 physical core has 8 logical cores thanks to HTT and BOINC is reading your CPU correctly.
	ID: 1120416 ·

Todd Madson Send message Joined: 4 Aug 99 Posts: 55 Credit: 15,927,766 RAC: 9,915	Message 1120688 - Posted: 24 Jun 2011, 2:18:26 UTC
	You will actually get better results if you let it crunch eight. ____________
	ID: 1120688 ·

Charles Michael Fulton Send message Joined: 13 Nov 09 Posts: 8 Credit: 170,900 RAC: 499	Message 1121761 - Posted: 26 Jun 2011, 18:38:00 UTC - in response to Message 1120688.
	Good to know! Hyperthreading tech, eh? Neat!
	ID: 1121761 ·

Questions and Answers : Macintosh : Benchmark Results show too many CPUs