Allocate up to 4G of RAM in LabVIEW

[MikaelH]

4G of RAM when running Vista 64 bit

Everywhere you read it tells you that you can allocate 4G of RAM when running LabVIEW on Vista 64 bit OS.

But I can’t get it working, on my VISTA-64 machine that has 8G of RAM installed.

First thing I found is that when running a small memory hungry application in LV8.6 development environment it can allocate more memory compared when I run it as an executable.

The “Size” value could be 32767 on Vista-64 in when running it from the development environment, but only 28623 when running it as an exe.

Maybe why “Size” only could 32767 (2^16)/2 is a limitation of how big LabVIEW allows arrays to be.

When using the value 32767, LabVIEW allocated 1.07 G of RAM, I can see this in the task Manager also.

The Value 28623 corresponds to only 0.82G. Why can I only allocate 0.8 in one array in an executable?

So if there where a limit of how big one Array could be, I copied the code above so 2 arrays of the same size should be allocated, that means 2.14 G of RAM.

(I could actually only set the Size to 32729. before I got Out Of Memory)

So I could only allocate 2G of RAM.

So what am I doing wrong?

The scariest thing is when I convert this second application into an executable. The application gets limited to 0.8G of RAM. I could only get the Size value up to 20300 which is 0.82G.

Cheers,

Mikael

[MikaelH]

I’ve gotten some answers from NI regarding my problem.

First there is a known bug in LabVIEW that prevents the runtime engine to allocate as much memory as the development environment.

Second problem is that I tried to allocate a big chuck of memory at once. If Windows can’t give LabVIEW a continuous bit of memory from the RAM with this size you get the “Out Of Memory” message.

There are memory defragment program that can make it better.

I tried to allocate many small chucks of memory than it works better, but still an executable can’t allocate as much as I can from the development environment.

//Mikael

[crelf]

QUOTE (MikaelH @ Jan 22 2009, 11:49 PM)

First there is a known bug in LabVIEW that prevents the runtime engine to allocate as much memory as the development environment.

Do you know wha tthe numbers are? ie: how much we can allocate in the RTE vs the Dev Env?

[JohnRH]

QUOTE (MikaelH @ Jan 22 2009, 11:49 PM)

I’ve gotten some answers from NI regarding my problem.

First there is a known bug in LabVIEW that prevents the runtime engine to allocate as much memory as the development environment.

Second problem is that I tried to allocate a big chuck of memory at once. If Windows can’t give LabVIEW a continuous bit of memory from the RAM with this size you get the “Out Of Memory” message.

There are memory defragment program that can make it better.

I tried to allocate many small chucks of memory than it works better, but still an executable can’t allocate as much as I can from the development environment.

//Mikael

NI has "LabVIEW 64bit Pioneer" available under their beta test program. (go to "www.ni.com/beta")

If beta software is an option, then you may find this helpful.

[MikaelH]

QUOTE (crelf @ Jan 24 2009, 01:28 AM)

Do you know wha tthe numbers are? ie: how much we can allocate in the RTE vs the Dev Env?

No, I don't know what the numbers are, but a single array could not be larger than 0.8G that's for sure.

Regarding switch to a 64 bit Beta, I don't think I dare.

Cheers,

Mikael