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Date:   Tue, 10 Jul 2007 04:24:43 -0400
Reply-To:   Gerhard Hellriegel <gerhard.hellriegel@T-ONLINE.DE>
Sender:   "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:   Gerhard Hellriegel <gerhard.hellriegel@T-ONLINE.DE>
Subject:   Re: varying SAS cpu usage

Another question: why do you think, 99% CPU consumption is good? If you have an IO intensive task which needs much cpu, there might be a problem! The goal is, to make IO as fast as possible. In that case, the cpu usage should be low. Not 0, but like you said, 5-10% should be ok. If it is 99%, you might have a problem with some calculations, branches, loops. Maybe there is potential for optimizing. Maybe not, if the logic is already optimized. If you were on a zOS mainframe, you'd detect a serious problem for a batch job, if it is using much CPU and makes no IO. That is a critical loop situation and the job must be stopped. On Win you can use the task-manager. If you see the IO rate high and cpu low, that is good for mass-data. Gerhard

On Tue, 10 Jul 2007 18:10:27 +1000, David Johnson <d@DKVJ.BIZ> wrote:

>SAS uses as much cpu as it needs to perform a task. Usually it consumes >quite low amounts of cpu because the machine is engaged in the business of >I/O and everything else waits on the data coming off the disk. > >I can sometimes get high cpu usage in a SAS session, but generally only in >array processing. > >You can look at the cpu rate yourself by step if you include the statement >Options FullSTimer; which will include details on run time, CPU time and >memory usage for each step. > >Kind regards > >David > > >-----Original Message----- >From: SAS(r) Discussion [mailto:SAS-L@LISTSERV.UGA.EDU]On Behalf Of bagavosd >Sent: Monday, 9 July 2007 11:59 PM >To: SAS-L@LISTSERV.UGA.EDU >Subject: varying SAS cpu usage > > >Dear All, > >I frequently run code written in SAS (under win XP, both on Pc's and >servers) that processes large amounts of data sets (more than 10 >billions of observations). Throughout the runtime of the SAS job the >cpu usage of SAS.exe ranges from 5% to 99%. Does anybody knows if this >is normal (i.e. is this the default behaviour of SAS) ? If yes, is >there any way to force SAS to use 99% of the cpu ? > >Thanks in advance > >Dimitris


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