[R] CPU Usage with R 2.1.0 in Windows (and with R 2.3.1)

[Uwe Ligges]

Duncan Murdoch wrote:
> Markus Preisetanz wrote:
>> ... I have exactly the same issue with R 2.3.1 . The Question is: Why is R unable to take more CPU space to make the calculation process go faster?
>>  
>> In my case no hardisk nor any network device is involved (data in RAM, 600 of 1024 MB filled) - and the CPU usage of the rgui-process does not exceed 50%.
>>  
>> Has anybody an idea? Is there a setting a can change?
>>   
> You are probably on a dual core or hyperthreaded machine.  R does almost 
> all of its work in one thread, so it will max out the usage on one cpu, 
> but not more than one.
> 
> If you are on a hyperthreaded machine, you can disable hyperthreading 
> and the report should show 100% usage, but that doesn't mean things will 
> be going twice as fast.  (I have heard that hyperthreading does slow 
> down some computations, so turning it off might be a good idea, but I 
> have never done the measurements myself.)

Highly depends on the task. I have seen two WinBUGS processes on a 
hyperthreading machine making full use of hyperthreading and surpisingly 
completing *both* in the same time as one on the same machine with 
hyperthreading disabled. I don't think Intel folks will find many of 
such impressive examples ...

Uwe Ligges



> 
> Duncan Murdoch
>>  
>> Sincerely, Markus
>> ____________________________
>> Markus Preisetanz
>> Consultant
>>
>> Client Vela GmbH
>> Albert-Roßhaupter-Str. 32
>> 81369 München
>> fon: +49 (89) 74217-113
>> main: +49 (89) 74217-150
>> fax: +49 (89) 74217-250
>> markus.preisetanz at clientvela.com <mailto:markus.preisetanz at clientvela.com> 
>> http://www.clientvela.com <http://www.clientvela.com/> 
>>  
>> Diese E-Mail enthält vertrauliche und/oder rechtlich geschützte Informationen. Wenn Sie nicht der richtige Adressat sind oder diese E-Mail irrtümlich erhalten haben, informieren Sie bitte sofort den Absender und vernichten Sie diese Mail. Das unerlaubte Kopieren sowie die unbefugte Weitergabe dieser E-Mail ist nicht gestattet.
>>  
>> This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received the e-mail in error) please notify the sender immediately and destroy this e-mail. Any unauthorized copying, disclosure or distribution of the material in this e-mail is strictly forbidden
>>  
>> xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>> From: Doran, Harold <HDoran_at_air.org <mailto:HDoran_at_air.org?Subject=Re:%20%5BR%5D%20CPU%20Usage%20with%20R%202.1.0%20in%20Windows> > 
>> Date: Wed 20 Jul 2005 - 04:59:34 EST
>>
>>
>>
>> Dear Michael: 
>>
>> Why is it a problem that R is not using more CPU space than it seems to need? 
>>
>> -----Original Message----- 
>> From: r-help-bounces at stat.math.ethz.ch 
>> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Greene, Michael Sent: Tuesday, July 19, 2005 2:29 PM 
>> To: 'R-help at lists.R-project.org' 
>> Subject: [R] CPU Usage with R 2.1.0 in Windows 
>>
>> 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. 
>>
>> The program used to be able to use more of the computer, but does not now. 
>> I don't believe this is a multiple processor machine. 
>>
>> Can anyone give any advice on how to solve the problem? 
>>
>> Thanks, 
>>
>> Michael Greene 
>>
>> Product Management 
>> Plymouth Rock Assurance Corp 
>> 617-951-1682 
>>
>>
>> 	[[alternative HTML version deleted]]
>>
>>   
>> ------------------------------------------------------------------------
>>
>> ______________________________________________
>> R-help at stat.math.ethz.ch mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.