Hello!

Advice me please, which API function best suits for creating (and managing)
13 dynamical arrays consisting of approx. 20000 elements each, every element (structure) weights not more than 1kb of data.

In my opinion you have to rethink thw whole algorithm you want to use Why do you need 250 megs of allocated memory? System won't let you do this even though I guess... Your program would need at least 512 MB RAM, so I think it's a bit too much.

But if I had to decide which one to use, I would use VirtualAlloc, as it uses pagefile and is better for large amount of data. Using HeapAlloc is afaik not considered good, when playing with such big data.

VirtualAlloc lets you commit large amounts of memory, while HeapAlloc allows you to reallocate. Since your array sizes won't change VirtualAlloc would be your best shot.

You may also want to look into a File Mapping Object, CreateFileMapping/ViewFileMapping you can read and write large amounts of data to the filemapping obj easily.