Chunks are 10 MB, so 2 gig for the one contiguous file, the file sequence files are 10 MB.

It takes 5 seconds to read the single file, 20 seconds to read the sequence.

Btw, I've read more about the format I am dealing with, and realized it is possible to gaurantee the max file size so I am now reading the entire file in a single call. So it looks like this:

Open file
Get file size (GetFileSizeEx)
Read entire file
Close

Is there maybe some kind of file pool I need to use for this kind of task? Or some way to prefetch information about files later in the sequence if it can be helped by a cache of some kind (file table info?)