Desktop ETS & Realtime RAM Limit

[MSATLAB]

Hello,

     I have a Desktop ETS system that is running Labview RTOS version 8.2.  The computer currently has 3 GB of Ram in three Dimms (1,2,&3).   When I try to add the fourth stick of Ram, I get a bunch of errors mostly containing random letters and numbers.  The last error states "ETS Monitor halting with error code 200D."  I am not sure what that means but I have a feeling that it has to do with the memory limit that RTOS can handle in 8.2.  I searched on Ni's website but did not find anything, or even anything documenting the system requirements in terms of Ram.  All four of the Ram sticks are of the same model and make.  So if someone could point me in the right direction and shed some light on this subject I would greatly appreciate it.  Thank you.

Michael

[RDR]

What motherboard are you using in the current machine?  There is the possibility this is a limit on the motherboard.

-Bob

[MSATLAB]

Hello,

     The Ram limit is not on the motherboard side of things.  I can boot into Windows XP with 4 GB even though Windows XP only notices 3 GB.  So I know that the problem is not the motherboard.  Thank you.

Michael

[Matt_W1]

Have you run a memory test on the last stick to make sure it's good (lookup memtest86+)

Anyway if ETS is like windows the last ~.5GB to 1GB is used up by devices, and can never be used. The only way around it in on a 32 bit x86 system is if the OS supports PAE (I think all current hardware physically supports PAE) and the memory controller can remap stuff so the devices and ram don't overlap, In windows PAE is only on the really high end versions (like data center or XP pre SP2, PAE was removed because a lot of device drivers couldn't work with it and that would cause a lot of problems). Note: windows may say that PAE is active when it really isn't (they need part of it for DEP). I'm not sure if PAE is enabled on ETS but I doubt it. Also in windows a single process could normally use a maximum of 2GB of memory (unless it was has the LARGEADDRESSAWARE flag enabled which raises the limit to 3GB (4GB if it runs under a 64bit os), but that only works if you also have the /3GB boot.ini flag enabled (not meaningful under 64 bit). AWE could be used to access more than 2GB (but I doubt you can use it in LabVIEW, and from what I've heard it's a pain to work with).

Basically what I'm saying is most likely (since I'm not sure how different the memory system is between ETS and Windows) if you have one process your can't use over 2GB of memory, and if you have multiply processes you can't use over 3-3.5GB, so the last stick of ram probably won't help you even if it did work.

Matt W

Message Edited by Matt W on 08-29-2007 05:52 PM