Subject: Re: Dell PowerEdge 8450
To: Toru Nishimura <>
From: David Burren <>
List: tech-smp
Date: 03/01/2004 15:18:13
"Toru Nishimura" <> wrote:
> His lab tested HT servers and concluded _the_ HT SMP Linux kernel
> implementation scales actually worse, at least no better, than
> plain SMP kernel.  It sounded HT is rather waste of transistor
> and electricity.

My understanding is that HT can be beneficial if you have a model
where you can avoid having threads from separate processes running
on the same physical CPU.

Given that this requires the use of multithreaded applications in
your performance critical path to get any advantage, and a scheduler
that distinguishes between virtual and physical CPUs, then without
both of those yes I'd agree it's a waste of time.
But I'm sure there's an application for it _somewhere_... ;)

Does anyone know of a scheduler (in any OS) that is HT-aware in
this way?
David Burren