How much memory can I use/have on Matlab 2012a 64 bit

To make use of the extended memory should I install the 64 bit version of Matlab either on Windows 7 64 bit or windows XP 64 bit.

I have to manipulate some very large number arrays - having about 50 million rows and 4 columns. Each number in the array is of the order of one billion. Is there any limitation in matlab as to the maximum array sizes or is it purely a matter of the amount of RAM I have allocated on my 64 bit OS.

Is it correct to say that if I use a 32 bit version of Matlab like Matlab 2008, the maximum memory I can allocate to my Arrays is 4GB?

Thanks in advance for your help

Answer 1

[Jan]

The command computer replies the maximum number of elements an array can contain on the local system:

[C, MAXSIZE] = computer

For a 32-bit Matlab (on a 32 or 64 bit system), MAXIZE is 2.1475e9, which is 2^31. When the type of this array is e.g. double each element has 8 bytes, such that the array would require 16 GB.

On my Win7/64/Matlab 2009a/64 I get MAXSIZE as 2.8147e14.

On a 32 bit OS the size of the accessible RAM is limited to 3 or 3.5 GB depending on the system board. Therefore applications operating on large arrays require a modern 64 bit system.