Building a High-Performance Cluster with Gentoo
Posted Apr 10, 2007 19:10 UTC (Tue) by rsidd
In reply to: Building a High-Performance Cluster with Gentoo
Parent article: Building a High-Performance Cluster with Gentoo
In my experience, the performance of system binaries is usually almost irrelevant to scientific code. What matters is how you compile your own code and perhaps a few key libraries like the BLAS, but in neither case do you need to recompile your whole OS.
Exactly. It's not "almost" irrelevant, it's entirely irrelevant. (Well, the kernel may cause a tiny difference -- nothing you could measure, I imagine -- but no other system binary should matter at all.) Compile your program, and possibly dependent libraries, with the relevant C flags and you're fine.
And, as you say, tweaking compiler flags is a lazy and unproductive approach. Usually if you profile your program and find the time-consuming bits, you can optimise those and get the sort of speed boost no compiler could ever give you.
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