finding most common elements between thousands of multiple arrays.

[MRAB]

mclovin wrote:
[snip]
> like I said I need to do this 480,000 times so to get this done
> realistically I need to analyse about 5 a second. It appears that the
> average matrix size contains about 15 million elements.
> 
> I threaded my program using your code and I did about 1,000 in an hour
> so it is still much too slow.
> 
> When I selected 1 million random elements to count, 8 out of the top
> 10 of those were in the top 25 of the precise way and 18 of the 25
> were in the top 25 of the precise way. so I suppose that could be an
> option.

The values are integers, aren't they? What is the range of values?