> 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. - R.
