Large Arrays in Visual C++ 2005

[beanwacked]

Hi,

I am writing a GUI that is used to acquire data from a high speed digitizer system with up to 16 channels. Each channel can acquire and store up to 256MS (each sample is 16bits).

The current system I am using has 4 channels and I would like to be able to read all 256MS from one channel into my software for processing and storage. The GUI is a CLR enabled Windows Form written in C++. Originally I was using "gcnew" to dynamically allocate my arrays (4 X numsamps), but I could only get up to 20MS before getting System.OutOfMemory exceptions. I assumed it was because I was fragmenting the managed heap and switched to using the unmanaged heap and the "new" operator. This got me up to 60MS X 4 channels before getting an unmanaged exception. Now, that is a ton of samples, but I would think that I could get more because when I allocate 60MS X 4 channels, there is still over 1GB of physical memory and 1GB of virtual memory available in the system. Is Windows XP holding this memory hostage or something? I would appreciate any tips/suggestions you can give.

Thanks!