Maximum use of RAM with one program

I am running Windows 7 Professional 64-bit with 4GB of RAM (3.87GB useable) with an Intel i5-3320m at 2.60Ghz.

I have started to use a different program for digital moving map display. The previous one could only display one map at a time, but the new one can overlay multiple maps. However it keeps reporting "Insufficient main memory" in a panel titled "DAVINCI grafikbibliothek", when adding more than three maps.

A Google brings up in German language information about 'DaVinci 4 : Quick Start Delphi' when translated. But the current version of the program is developed within Visual Studio 2013 and Xamarin.

I know that 32-bit W7 can only use 2GB of RAM, but as I'm using W7 64-bit, I should be able to increase my existing 4GB of RAM. But will this increase the memory available to the program, which is only 32-bit?

By default a 32 bit process has a 2 GB virtual address space. If the process is Large Address Space Aware (most are not) and running on a 64 bit OS this will become 4 GB. Unless the process is using special methods (most do not) a 32 bit process will normally be limited to about 2 GB RAM but will typically use substantially less.

A shortage of RAM rarely causes problems other than a loss in performance. Error messages usually mean exhaustion of process virtual address space or reaching the commit limit. The "Commit (MB)" item in Task Manager will show the current commit and the commit limit. With default pagefile configuration that is unlikely to occur but it sometimes happens when changes are made.

If the problem is exhaustion of the process address space there is very little you can do. This problem is the primary reason why 64 bit operating systems were developed. A 64 bit will potentially provide each process a 8 TB address space (independent of RAM size) but only native 64 bit applications can take advantage of that.

AddRAM said:

Who told you W7 32 bit can only use 2 GB ram ?

It can use 3.5 to 3.75.

If your motherboard supports more then 4 GB of memory then by all means, add as much as you can afford.

Post a manufacturer`s link to the motherboard, we can then research :)

Sorry confusion with user-mode virtual address space for each 32-bit process, as seen on a Microsoft web page.

I need to have more memory available to a single 32-bit program, not to all programs.

The PC is a Panasonic Toughtbook CF-53, running 64-bit OS.

Regarding the patch mentioned in post #6.

In theory any application could have a virtual address space of 4 GB on a 64 bit OS. The problem is that many of these have issues that would cause them to malfunction in a 4 GB address space environment. The application developer may or may not be aware that the application has these problems. For that reason 32 bit applications are given a 2 GB address unless they explicitly indicate to the OS that they are compatible with the larger address space. If that is the case we can reasonably assume that the application developer is aware of the potential problems and has taken the necessary steps to avoid them. Unfortunately that isn't always the case.

The patch does not make the application compatible as that is something only the application developer can do. What it does do is mark the application as "Large Address Space Aware", indicating that it is compatible. The problem is that you may be forcing the application to lie about it's capabilities. In that case results are unpredictable but tend to be unpleasant. Many applications WILL fail if this is done.

If you use the patch be sure you are aware of the risks. If you are lucky the application will immediately crash if not compatible. If you are not so lucky it may silently corrupt your data. Or the application may work fine most of the time but fail only under specific, possibly rare, conditions.

Many thanks LMiller7 for your two most informative postings. I had been searching the internet for more information as my own knowledge of computer hardware and software is much like me - getting rather old! I'm now retired after starting in the PC business in 1978. Unfortunately there is so much incorrect information available.

As an example; I've read that on a 64-bit OS, page file swap to disk had gone.

I will contact the program's author, but expect that he won't be producing a 64-bit version. So no reason to increase RAM.