Off topic - G5 question

Vann H. Walke walkev at
Thu Jun 26 15:34:52 EDT 2003

> Alternatively, just compiling the same source with gcc with the same
> flags on both systems works for me, at least, as this is likely to be
> the extent of the effort I want to make tuning per architecture, ever.
> Maintaining architecture-specific optimizations in a changing world of
> hardware technology is very painful and expensive.

I pretty much agree with all your points, but don't completely ignore
optimizations.  For some of our signal processing code, we get a ~2.5x
speedup by using SSE primitives.  It is isn't hard to justify a couple
days of weeding through code to reduce your hardware requirements by
half.  Plus, at least for the SIMD type instructions porting to other
SIMD architectures isn't excruciatingly painful.  We were able to tune
our code for both the Altivec and SSE instructions, thus giving us
"real" performance comparisons.


Vann H. Walke <walkev at>
Presearch, Inc.

Beowulf mailing list, Beowulf at
To change your subscription (digest mode or unsubscribe) visit

More information about the Beowulf mailing list