On 2006-02-18, at 15:23, Joern Rennecke wrote:
In http://gcc.gnu.org/ml/gcc/2006-02/msg00357.html, you wrote:
In fact the "gamer" benchmarks you are dissing are quite well
reflecting the
very kind
of coding excessively found in GCC itself. Some observations suggest
the you should aim at the CPU with the biggest L2-cache size
affordable. In
particular
comparision on the older Athlon XP line where very conclusive here
as there
where similarly rated CPUs available with 256kB vers. 512kB caches.
Usually the
512k where 20% faster on GCC build loads then the ones with smaller
caches
despite beeing significantly lower clocked.
By that token, the Pentium D 920 should trounce the Athlon X2 3800
+ . But
that's
not what these benchmarks show.
Well the Pentium D has an severe execution pipeline "complex" in
combination with recessive memory access latency "syndrome", which it
"overcompensates" with huge caches and clock "overactivity". I taught
we where talking only about "mentally sane" architectures here.
More seriously: The Netburst architecture fits well DSP tasks and
certainly doesn't lend well to decision oriented tasks, which is what
GCC does most of the time. Pretty pure locality of code in GCC
strikes bad as well. For compilation tasks an opteron with big caches
and as many cores as possible of course has right now the best bang
for the money. The rest basically depends just on budget.
