Information on the number of CPU's
Many thanks, that's very helpful. Regards, Tolga ----- Original Message ----- From: Prof Brian Ripley [ripley at stats.ox.ac.uk] Sent: 09/09/2008 20:57 CET To: Tolga Uzuner Cc: r-help at r-project.org Subject: Re: [R] Information on the number of CPU's
On Tue, 9 Sep 2008, tolga.i.uzuner at jpmorgan.com wrote:
Dear R Users, I am on Windows XP SP2 platform, using R version 2.7.2 . I was wondering if there is a way to find out, within R, the number of CPU's on my machine ? I would use this information to set the number of nodes in a cluster, depending on the machine. Sys.info() and .Platform do not carry this information.
Correct, since a) R does not make use of more than 1. b) It is really not portable, and not even well-defined. (How many CPUs has a hyperthreaded dual Xeon? Some say 2, some say 4. Do you want CPUs or cores? If this is a virtualized OS, is the physical number or the logical number?) In the case of Windows, how depends on the Windows version. The w32api (XP or later) call GetNativeSystemInfo will tell you the number of CPUs, for some (unstated) definition of 'CPU'. Later versions have GetLogicalProcessorInformation, which can give the number of cores.
Thanks in advance, Tolga Uzuner
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 Generally, this communication is for informational purposes only and it is not intended as an offer or solicitation for the purchase or sale of any financial instrument or as an official confirmation of any transaction. In the event you are receiving the offering materials attached below related to your interest in hedge funds or private equity, this communication may be intended as an offer or solicitation for the purchase or sale of such fund(s). All market prices, data and other information are not warranted as to completeness or accuracy and are subject to change without notice. Any comments or statements made herein do not necessarily reflect those of JPMorgan Chase & Co., its subsidiaries and affiliates. This transmission may contain information that is privileged, confidential, legally privileged, and/or exempt from disclosure under applicable law. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or use of the information contained herein (including any reliance thereon) is STRICTLY PROHIBITED. Although this transmission and any attachments are believed to be free of any virus or other defect that might affect any computer system into which it is received and opened, it is the responsibility of the recipient to ensure that it is virus free and no responsibility is accepted by JPMorgan Chase & Co., its subsidiaries and affiliates, as applicable, for any loss or damage arising in any way from its use. If you received this transmission in error, please immediately contact the sender and destroy the material in its entirety, whether in electronic or hard copy format. Thank you. Please refer to http://www.jpmorgan.com/pages/disclosures for disclosures relating to UK legal entities.