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

Erik Wikström erik-wikstrom at
Wed Jun 6 06:08:20 PDT 2007

On 2007-06-06 14:30, km b wrote:
On 04 Jun 2007 11:58:18 GMT, Rahul Siddharthan <rsidd120 at> wrote:

I made no claim about "all" binaries, and I claimed the exact opposite
of what you say I claimed for my own binaries: I said the 32-bit
binaries are 50% slower than the 64-bit binaries.  (Eg, running time
25 secs for 64-bit, 38 secs for 32-bit.)
i did some homework for you and conducted the FFT benchmark (double
precision only, single precision disabled) of the specific library you
mention (GSL) using fftbench in two
different execution environments  on Intel Core 2 Duo 1.6G machine
1. pure 64-bit - FreeBSD , CFLAGS="-m64 -march=nocono -O3 -fomit-frame-pointer"

2. 32-bit - DragonFlyBSD, CFLAGS="-march=prescott -O3 -fomit-frame-pointer"

And here I am attaching the results for you to study. Let me know
where do you see the 50 % performance increase?
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.

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).

Erik Wikström

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