On Fri, 14 Apr 2006, David Cary Hart wrote:
In FC4, the optimization string include mtune=pentium4. Does anyone
know why this changed to mtune=generic? Is there a performance hit on
P4s? Has this been documented anywhere? IIRC, developers claimed
numerous performance benefits with the p4 tune.
The compilers/libraries have changed, as has the range of CPU's that may
need to run fc5. The average system running fc5 is faster than the
average fc4 system, so it makes sense to compile with reduced optimization
for reliability and simpler debugging. It is quite possible that the code
that was causing poor performance with mtune=generic has been rewritten or
replaced.
What matters is whether your hardware performs acceptably with fc5.
There are some apps (linear algebra, video encoding) that really must be
compiled for the specific hardware configuration if you use them heavily.
--
George N. White III <aa056@xxxxxxxxxxxxxx>
