RE: [condor-users] Pc's with hyperthreading

[Ian.McLeod@xxxxxxxx]

I will disabble it across the pool
I notice when I did the first machine I gained 300mips 
I want to run a better benchmark 
But on the surface it looks like there is a ~8% overhead
The computer in question runs windowsXP and as I understand it neither 
Windows or R take advantage of hyperthreads yet 

Ian 
 

-----Original Message-----
From: owner-condor-users@xxxxxxxxxxx
[mailto:owner-condor-users@xxxxxxxxxxx] On Behalf Of Erik Paulson
Sent: Friday, 23 April 2004 10:45 AM
To: condor-users@xxxxxxxxxxx
Subject: Re: [condor-users] Pc's with hyperthreading


On Fri, Apr 23, 2004 at 10:30:32AM +1000, Ian.McLeod@xxxxxxxx wrote:
> Our latest crop of Pc's are coming with hyperthreading
> The computers are pretending to have 2 cpu's
> 
> Two questions
> 1. How do I want to convince condor that it really has only one CPU
>    I found the NUM_CPUS in the config file - 
>    but I note that its use is not recommended. 
> 

For disabling hyperthreading, that is the recommended solution.
Many machines will let you disable hyperthreading in the BIOS
as well.

In Condor 6.6.5 (still a few weeks off), we have a 
COUNT_HYPERTHREAD_CPUS = FALSE

option, which will detect if some of the CPUs are hyperthreads
and not count them, so you can set this as a global config file.

It's currently a Linux-only option, we'll see if we can make it work
on Windows too.

> 1. How good is the hyper-threading technology ? 
>    Should I be trying to convince condor that it really has only one
CPU

As with all things HPC, it depends on the app :)

For the most part, here at UW we've disabled it to keep the RAM per 
virtual machine high.

-Erik
Condor Support Information:
http://www.cs.wisc.edu/condor/condor-support/
To Unsubscribe, send mail to majordomo@xxxxxxxxxxx with
unsubscribe condor-users <your_email_address>

Condor Support Information:
http://www.cs.wisc.edu/condor/condor-support/
To Unsubscribe, send mail to majordomo@xxxxxxxxxxx with
unsubscribe condor-users <your_email_address>