Question PAE and other memory questions

[lakedude]

Man I don't even know were to start or which sub-forum would be the most appropriate. We have a fancy machine at work and when it runs mechanically slower the machine's computer seems to be able to keep up and we don't have any real problems with it. Of course they don't want to run the machine slow. When the machine runs faster it seems like the the computer can't keep up which leads to a lot of machine shutdowns and computer reboots. My idea is to see what we can do to speed the computer up in some fashion.

So the computer has a SuperMicro MB model X8DA3/X8DAi and dual Xeon E5520 CPUs. The board supports triple channel memory with 6x slots per CPU.

You will not believe how much memory is in these computers. Perhaps even more strange is the OS they are running. Any guesses?

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Memory 4x 1GB sticks 2x per CPU.
OS Windows XP Pro 32 bit.

The OS displays 2.99GB of ram which I don't understand. I'm told XP supports up to 4GB.

What would be the optimal configuration for such a system?

I suspect that the computer is bogging down for lack of RAM but I'm not sure the OS will allow for much if any additional.

I'm wanting to install an SSD in hopes that if the system is hitting virtual RAM at least the SSD could keep up somewhat.

Changing the OS to a more appropriate one is not really possible (at my level) because of the machine specific application.

EDIT: I forgot that the screen under Control Panel/System shows PAE. As I understand it PAE should allow some sort of ability to use over 4GB but evidently it is not always enabled.

 

[Insert_Nickname]

Memory 4x 1GB sticks 2x per CPU.
OS Windows XP Pro 32 bit.

The OS displays 2.99GB of ram which I don't understand. I'm told XP supports up to 4GB.

What would be the optimal configuration for such a system?

I suspect that the computer is bogging down for lack of RAM but I'm not sure the OS will allow for much if any additional.

I'm wanting to install an SSD in hopes that if the system is hitting virtual RAM at least the SSD could keep up somewhat.

Changing the OS to a more appropriate one is not really possible (at my level) because of the machine specific application.

EDIT: I forgot that the screen under Control Panel/System shows PAE. As I understand it PAE should allow some sort of ability to use over 4GB but evidently it is not always enabled.

32bit Windows only support 4GB with caveats. Depending on system and configuration 3 to 3.5GB is available to the OS. The rest is reserved for hardware, and can't be accessed.

PAE isn't a magic bullet to solve your issue with memory. Theoretically, PAE mode allows up to 64GB on a 32bit system. But an application has to be PAE aware for it to be able to utilise it. Otherwise you get the normal 2GB per application limit.

Only way to access more memory is moving to an x64 OS, which isn't an option in this case. BTW, this won't solve the 2GB limit if the application is only 32bit. It still can't access more memory, but x64 Windows can map a 32bit application into its own 2GB "rubber cell", which it doesn't have to share.

What you -can- try is putting an SSD into the system. This will, if not eliminate, then at least significantly reduce any disk I/O bottlenecks. Even the slowest SSD is an order of magnitude faster then any HDD (100IOPS vs. 50.000+ IOPS)

You will not believe how much memory is in these computers.

4GB? That isn't much today.

4GB is still acceptable'ish for basic stuff. I wouldn't go lower then 8GB today. My own main system has 32GB of memory.

 

[nosirrahx]

Sometimes you can 'fake' your way around the memory restriction of XP by installing RAM drive software that lets you take RAM outside of the 32bit address space and create a virtual drive there.

Next move the page file to this drive and set a fixed size equal to the size of the RAM drive.

This can help speed up older systems SOMETIMES by taking a part of the OS that already exists (paging data to disk to create additional virtual RAM) and put that paged data into RAM by directing it to that RAM disk.

 

[JoeBleed]

looking at the task manager, what is your ram usage? CPU usage? dig around to find the app to check hard disk usage or at least look at the HDD activity light and see how much it's blinking.

I've had several instances where the user thinks they need more ram or cpu when dealing with software modifying PLCs at work. Many time's it's not related to the ram or cpu.

 

[nosirrahx]

^That is true. More than anything switching from HDD to SDD can make an old system feel blazing, this also addresses the paging issue as paged data on a SSD is not at all like paged data on a HDD.

 

[lakedude]

Thanks for the replies. I've got an SSD on order. We have more RAM we could put in but we have not because the OS won't use it as currently configured. Using a RAMdrive sound like a great idea, except when I look it up they say that the app will only use memory that the OS can already see, effectively taking usable memory away. In order for a RAMdrive to work the way we want it would need to run outside Windows and outside Windows' limitations. Does such a thing exist?

 

[nosirrahx]

Thanks for the replies. I've got an SSD on order. We have more RAM we could put in but we have not because the OS won't use it as currently configured. Using a RAMdrive sound like a great idea, except when I look it up they say that the app will only use memory that the OS can already see, effectively taking usable memory away. In order for a RAMdrive to work the way we want it would need to run outside Windows and outside Windows' limitations. Does such a thing exist?

That is untrue. Way back when I had a dual boot laptop (XP and 7 64) I had 8 gigs installed and used a RAMdrive in XP to make use of the unaddressable RAM.

I am never going to remember the name of the software now but with a quick search I am finding a few products that can do this.

https://www.megaleecher.net/RAMDisk

http://www.romexsoftware.com/en-us/primo-ramdisk/index.html

 

[lakedude]

Very good, thank you!