P4 Hyperthreading

Message boards : Number crunching : P4 Hyperthreading

Author	Message
Majix Send message Joined: 6 Apr 99 Posts: 1 Credit: 169,223 RAC: 0	Message 1068 - Posted: 24 Jun 2004, 9:25:26 UTC
	I'm getting some very poor results on a P4C 2.8GHz HT machine: 455 double precision MIPS (Whetstone) per CPU 806 integer MIPS (Dhrystone) per CPU Even if you double it for 2 logical CPUs it's still very bad. I was thinking, maybe the Boinc client doesn't understand that the two CPUs reported by the OS aren't physical and is doing some very poor load balancing choices causing cache trashing? I don't want to test with Hyperthreading off at the moment, because I can only connect remotely with SSH to the system. Has anyone else done some real HT tests?
	ID: 1068 ·

Heffed Volunteer tester Send message Joined: 19 Mar 02 Posts: 1856 Credit: 40,736 RAC: 0	Message 1071 - Posted: 24 Jun 2004, 9:32:40 UTC
	Yes, hyperthreading is known to confuse the benchmarks. Benchmark with hyperthreading turned off for more accurate results.
	ID: 1071 ·

STE\/E Volunteer tester Send message Joined: 29 Mar 03 Posts: 1137 Credit: 2,849,884 RAC: 1,437	Message 1074 - Posted: 24 Jun 2004, 9:42:41 UTC Last modified: 24 Jun 2004, 11:23:08 UTC
	Are you using the latest version of Seti@Home out Majix v3.19, your benchmark score looks more like what a older version would report. I'm getting between 1700 & 2100 double precision MIPS (Whetstone) per CPU on my HT PC's depending on how I test it with the v3.19, with or without HT turned on.
	ID: 1074 ·

DPRGI - Marzio Nieddu Send message Joined: 14 Feb 00 Posts: 5 Credit: 2,166,030 RAC: 0	Message 1079 - Posted: 24 Jun 2004, 10:31:13 UTC
	I agree with PoorBoy , your benchmark is very low or you have something that run with BOINC, have you check the taskmanager ? cheers SETI@Home ITALIA - Team DPRGI 1° Italian Team in Seti@Home Classic
	ID: 1079 ·

Message boards : Number crunching : P4 Hyperthreading