Re: [R] CPU Usage with R 2.1.0 in Windows

From: Prof Brian Ripley <>
Date: Wed 20 Jul 2005 - 18:12:07 EST

It probably is not a problem to leave hyperthreading on: we found little performance difference on a P4 either way.

The Windows task manager is misleading, as `50%' is about as much as a P4-class processor with hyperthreading can actually deliver.

On Tue, 19 Jul 2005, Lukasz Komsta wrote:

> Dnia 2005-07-19 20:28, U˙˙ytkownik Greene, Michael napisa˙˙:
>> Hi,> > I'm using a fairly simple HP Compaq desktop PC running Windows 2K. When> running a large process in R, the process "RGUI.exe" will never exceed 50%> of the CPU usage.
> If you have hyperthreading, R catches only one virtual processor (fromtwo available), being not able to exceed half of total power (100% ofone only). If you want to use full power, you should turn hyperthreadingoff, if your BIOS supports such option.
> Regards,
> -- Lukasz KomstaDepartment of Medicinal ChemistryMedical University of Lublin6 Chodzki, 20-093 Lublin, PolandFax +48 81 7425165
> mailing list do read the posting guide!

Brian D. Ripley,        
Professor of Applied Statistics,
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

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Received on Wed Jul 20 18:17:38 2005

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