This thread comes up every year I reckon - and then we all have a fight about who is right (when really, we all are) but even so, we often end up not speaking to each other for a couple of days like a too-much-alcohol-family-christmas Still, thanks for the great article Jeremy - it was bookmarked somewhere as it's always useful to refer to. I'm going to pop this piece on citrixthings.com and then just post a link next time J From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of Jeremy Saunders Sent: 21 July 2011 14:22 To: thin@xxxxxxxxxxxxx Subject: [THIN] Re: Citrix Performance - Processor Scheduling and Memory Usage Mark R actually goes a bit more deeper than that, if you've read his books. That why I wrote this article, which Andrew kindly posted below: http://www.jhouseconsulting.com/2008/05/13/processor-scheduling-20 However, Andrew's comments are very true. Each and every setting effects the next. On a 32-bit system you are simply tweaking the way the 2GB Kernel memory space works. Every time you enhance one setting you are essentially robbing Peter to pay Paul. Cheers, Jeremy. From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of Webster Sent: Thursday, 21 July 2011 9:16 PM To: thin@xxxxxxxxxxxxx Subject: [THIN] Re: Citrix Performance - Processor Scheduling and Memory Usage David Solomon in his windows Internals class says to set it to Programs and he says Mark R. says the same thing. If you think about it, Exchange, SQL, etc runs lots of services and XenApp runs Programs (lots of them for lots of users). I will go with what David S. and Mark R. say. Thanks Carl Webster Consultant and Citrix Technology Professional http://www.CarlWebster.com <http://www.carlwebster.com/> (check out the changes coming to my website) _____ From: thin-bounce@xxxxxxxxxxxxx [thin-bounce@xxxxxxxxxxxxx] on behalf of Andrew Wood [andrew.wood@xxxxxxxxxxxxxxxx] Sent: Thursday, July 21, 2011 4:38 AM To: thin@xxxxxxxxxxxxx Subject: [THIN] Re: Citrix Performance - Processor Scheduling and Memory Usage The thing to remember about optimal Citrix performance is that - there is no one universal setting that will work for all environments every time: each environment can be different - test it first. And, think through effort-to-performance: you could spend weeks messing around with performance stats and end up getting an extra 2% performance - but really, would your punters notice? Still, gave me a chance to dust off this document from IBM on Windows 2003 tuning. http://www.redbooks.ibm.com/redpapers/pdfs/redp3943.pdf Anyhoo - there's a useful document from Citrix: Top 10 Items Found by Citrix Consulting on Assessments (http://support.citrix.com/servlet/KbServlet/download/18928-102-19722/Top%20 10%20Items%20Found%20by%20Citrix%20Consulting%20on%20Assessments%20v2.pdf) Which in turn leads you to the Citrix Advanced Concepts guide(s): http://support.citrix.com/article/ctx114746 In terms of that specific memory optimisation - I've always gone with setting it to system cache (not programs) and "background tasks" (not programs)* - which goes against some the generally excellent advice outlined here http://www.citrixtools.net/Resources/Articles/articleType/ArticleView/articl eID/36/Terminal-Server-XenApp-Tuning-Tips.aspx Memory The reg entry is LargeSystemCache HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management LargeSystemCache = REG_DWORD: 1 This setting allocates additional memory to the File System Cache. From Windows Server 2003, Microsoft moved the registry from Paged Pool RAM and into the File System Cache. Running out of File System Cache will prevent users' ntuser.dat files (profiles) from loading. http://smallvoid.com/article/winnt-system-cache.html With the suggestion of having a looksee at http://support.microsoft.com/kb/920739 Processor Usage To be fair, if it was just terminal services/rds on its own, the better setting would be "programs" - this is because this it sets the timeslice quantum to be nice and short - everyone getting a better crack of the whip. But in XenApp you can turn on funky CPU utilization management (other 3rd party CPU management tools are available) in which case you should set it to background services (otherwise you either get errors or the CPU utilization management doesn't work as effectively) And here's a nice article all about that - http://www.jhouseconsulting.com/2008/05/13/processor-scheduling-20 hth From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of Angela Smith Sent: 21 July 2011 01:23 To: thin@xxxxxxxxxxxxx Subject: [THIN] Re: Citrix Performance - Processor Scheduling and Memory Usage I was hoping there would be a clear answer to this.. I remember years ago reading about it and everyone had it set differently.. Hopefully someone can provide "best practice" advice on what it should be set to for optimal Citrix performance. _____ From: rich@xxxxxxxxxxxxxxxxxx To: thin@xxxxxxxxxxxxx Subject: [THIN] Re: Citrix Performance - Processor Scheduling and Memory Usage Date: Wed, 20 Jul 2011 16:40:58 -0400 Funny, I just a Citrix engineer tell me to set it to System Cache! _____ From: Mark.Landin@xxxxxxxxxxxxxxxx To: thin@xxxxxxxxxxxxx Date: Wed, 20 Jul 2011 15:38:25 -0500 Subject: [THIN] Re: Citrix Performance - Processor Scheduling and Memory Usage Memory Usage should be set to Applications (or whatever is NOT "System Cache"). _____ From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of Angela Smith Sent: Wednesday, July 20, 2011 5:21 AM To: thin@xxxxxxxxxxxxx Subject: [THIN] Citrix Performance - Processor Scheduling and Memory Usage Hi What is the correct setting for Citrix Performance. A default Windows 2003 R2 Server install defaults to: Processor Scheduling Programs Memory Usage System Cache Is this OK or should I change it? Thanks Ang _____ This message and any attachments may be a confidential attorney-client communication or otherwise be privileged and confidential. If you are not the intended recipient, any review, distribution or copying of this transmittal is prohibited. If you have received this transmittal in error, please reply by e-mail and delete this message and all attachments