Citrix, processes and memory usage

MasterPlan1 · 14 Aug 2009 at 10:51

I've got an annoying issue whereby we're setting up a system and this program which is currently using 1.7Gb of memory it generates large ammounts of data into a report. Now, when it hits the 1.7Gb mark, it fails, is there any limits as to how much memory (phys\virtual) that a process can use? I'm thinking not, as I'm sure I've seen exchange eating 2gb, and likewise with SQL... But I'm getting **** on from the powers that be, and me moaning that my servers\citrix are causing this issue.

Also, to clarify, Citrix is essentially just a pretty front end for what is at the end of it all, RDP? So, running this app is just like running it on the server?

Gerbil · 14 Aug 2009 at 14:14

If it's a 32 bit app then 1.7GB sounds about right as the upper limit of memory that a single process can use whether or not its running on a 64 bit OS.

Edit...should have added that if your running a 32 bit version of Windows there's always the /3GB switch that might increase the memory addressable by a single 32bit process to better than 2GB, but I've never tried using it. On a 64 bit OS if the application is large address aware then you might achieve 2.8GB for a single process.

MasterPlan1 · 14 Aug 2009 at 15:33

Thanks, this may have solved my problem. The software is a small company that wrote it, and we're the biggest company that they've ever worked with and we're migrating onto this new system from an already large system which is dated (but this new one can interface with some other software we use) so I'm not entirely sure that it will run with large address awareness and I don't think it's 64bit..

Gerbil · 14 Aug 2009 at 21:02

To be honest I've had similar problems with 32 bit apps on 32 bit Terminal servers just grinding to a halt when they hit the 2Gb memory limit. What amazed me was the surprising lack of understanding of the developers.They didn't have a clue when I asked them if their app was large address aware.

This article seems to suggest that 32 bit apps on a 64 bit OS get access to a full 4GB address space. You can always try modifying the flag in the EXE yourself (after backing up your data) and see if it makes any difference