12 Jul
2006
12 Jul
'06
7:40 p.m.
On Wed, 2006-07-12 at 18:20 +0200, Arnold Krille wrote:
2006/7/12, Roberto Gordo Saez
<roberto.gordo(a)gmail.com>om>:
So, a single turion64 is faster than and double xoen32. That's all that
the test says. It does not say "64 bit is faster than 32 bit".
To answer that question to an approximation you would have to install
the 32 bit version of the exact same distro that was running in the
turion64 in the turion64 machine. Then run the test again.
I've made tests mainly on big server
applications, I have not made
tests on audio software, so I suggest everyone to dedicate some time
testing your own apps. It is simple: make two partitions, one of them
with a 32bit OS, and the other optimized for 64 bit. Do not use a
chroot nor mixed environment (32bit libs on 64bit system), because the
results can be slightly different.
Okay, I don't have space (and time) for a second partition. And while
I understand that my testing might not be the optimum test, I think
your's isn't either: Because you compare fully using a 64bit system
with using a 64bit system in 32bit-mode. It is like comparing a big
motorcycle with the same motorcycle but slowed down. For sure the
slowed-down version will not be as fast. Also german IT-newspaper c't
has made some comparisons when opteron64 and intel xeons with 64bit
went onto the market Their result was that the amd64 are faster than
the intel64. And surprisingly enough the amd64 in 32-bit mode where
almost as fast as in 64-bit mode while the intels where significantly
slower in 32-bit mode than in 64-bit mode...
I am thinking about some other test, as someone mentioned registers
and memory and stuff, which I think are good to recognise, but for the
"real" computing speed maybe a mathematical test would be better? A
test that wouldn't need lots of memory and lots of registers and
doesn't have lots of cache-misses?
Like computing pi to a certain number of relevant numbers?
And, yes, I am comparing apples with oranges. But that was the
question at least here in the lab: Comparing single-turion64 with
double Xeon32. And guess what: On rather simple code, without special
SSE/MMX/etc optimisation, with the same compilerflags, the turion was
significantly faster. So I would like to prove this observation by a good
test. But
comparing a retarded 64bit system with a full 64bit system isn't the
solution. (Who would for example shut down half of the heating of his
toaster anyway?)
If the performance advantage of 64bit mode over 32bit mode (in the same
processor / distro version) is not big some users might prefer to stay
in 32 bit mode simply because there is stuff that will not (yet) run in
64 bit mode.
-- Fernando