On Sat, 7 Feb 2009, Jeff Squyres wrote:
End result: I guess I'm a little surprised that the difference is that clear -- does a function call really take 10ns? I'm also surprised that the layered C version has significantly more jitter than the non-layered version; I can't really explain that. I'd welcome anyone else replicating experiment and/or eyeballing my code to make sure I didn't bork something up.
That is significantly higher than I would have expected for a single function call. When I did all the component tests a couple years ago, a function call into a shared library was about 5ns on an Intel Xeon (pre-Core 2 design) and about 2.5 on an AMD Opteron.
Brian
