> Based on some discussion on this list, I integrated a zlib-based compression
> ability into ORTE. Since the launch message sent to the orteds and the modex
> between the application procs are the only places where messages of any size
> are sent, I only implemented compression for those two exchanges.
> I have found virtually no benefit to the compression. Essentially, the
> overhead consumed in compression/decompressing the messages pretty much
> balances out any transmission time differences. However, I could only test
> this for 64 nodes, 8ppn, so perhaps there is some benefit at larger sizes.
A faster compression library might change the balance... eg LZO
(http://www.oberhumer.com/opensource/lzo) might be worth a look although
I'm not an expert on all the compression libraries that are out there.