implemented features (Re: Decision time....)

km b kmb810 at gmail.com
Wed Jun 6 15:16:01 PDT 2007


On 6/6/07, Erik Wikström <erik-wikstrom at telia.com> wrote:

The place where he found the 50 % performance increase is indicated
right in the text you quoted, in *his* binaries compiled from *his*
code. He also did mention that this seemed to be true for *some* parts
of the GSL, not all of it. So unless you can get hold of the same
program as he is talking about and showing that there's no difference
between 64-bit and 32-bit machines then there's nothing you can do to
prove him wrong.
Rahul is a theoritical physicist and I am asking him to compare
oranges vs oranges and not apple vs oranges to back his claims.
AS for 32-bit machine vs 64-bit machines , there may be a massive
performance increase.
However on the same 64-bit machine, in two different execution
environments you won't see a massive performance shift as Rahul is
claiming. You can see some of the extensive benchmarking results at
http://www.fftw.org/benchfft/.

Regarding your tests I find it hard to put any faith into number derived
from running different tests (32 vs. 64 bits) on different machines (is
it even the same hardware?). By the way, the files you sent were not
PDFs, but PS-files (took me a while to figure that one out).
Read my mail. Same machine, same hardware, different execution
environments. I am comparing oranges vs oranges not oranges vs apples
to back my results.
Have fun

cheers
kmb
--
Something is wrong up on cloud # 9!





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