Date: Thu, 14 Mar 2002 17:01:18 -0500 (EST) From: Kenneth Culver <culverk@alpha.yumyumyum.org> To: Terry Lambert <tlambert2@mindspring.com> Cc: Steve Wingate <stevew@velosystems.net>, <freebsd-smp@FreeBSD.ORG> Subject: Re: Intel Xeon hyperthreading Message-ID: <20020314170017.I22063-100000@alpha.yumyumyum.org> In-Reply-To: <3C9118D6.81B9FD62@mindspring.com>
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> Kenneth Culver wrote: > > I don't know if anyone is working on that, but from what I could tell, in > > a lot of cases, enabling the hyperthreading actually *decreased* > > performance of a lot of multithreaded and single threaded apps. > > It requires extensive compiler support. > > If you read the Intel documentation on how to write a compiler > that does the right things, it reads like a list of sixteen > "don't do this thing GCC did, do this instead". > > So the answer is really a question... does the original poster > have their patches to GCC ready so that we can compile code > that tests hyperthreading? > Yeah, I know, but from what I hear a lot of people are misunderstanding what hyperthreading is, and they think it basically doubles performance. I posted with that in mind. :-) Ken To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message
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