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Re: Don't see much difference between i386 vs amd64



On Wed, Sep 08, 2004 at 12:37:22PM -0400, Mario Bertrand wrote:
> Hi,
> 
> I have successfully install debian with sid-amd64-monolithic.iso on my
> second ide (+kernel 2.6.8-3) and I don't see much difference in the
> performance vs i386 sarge (+kernel 2.6.8-1) on my first ide. It is
> normal? Should I expect more? Someone told me that I should buy a new
> hard drive with more cache (8M) to take benefit of faster cpu.

 If you have plenty of RAM (1GB), the OS won't need to keep loading programs
from disk all the time while they're running, because they won't get dropped
from the cache.  If whatever you're doing ends up waiting for the slow disk
very often, getting a faster one will help you.

> 
> hda  - 2048k cache - 3923.96 BogoMIPS	/ i386
> hdb  - 69k cache   - 3932.16    ""	/ amd64

 Try a benchmark instead of an idle-loop calibrator:
$ time bc -l
...
scale=1000
4*a(1)
quit

look at user time, not real time, if you type in the commands by hand.

IIRC, with some larger precision (scale=...), it's faster by 22s vs. 18s on
an Opteron 240.  (gcc-3.3 pure64 vs. i386 RedHat 9.)

 bonnie++ is a decent disk/filesystem benchmark

-- 
#define X(x,y) x##y
Peter Cordes ;  e-mail: X(peter@cor , des.ca)

"The gods confound the man who first found out how to distinguish the hours!
 Confound him, too, who in this place set up a sundial, to cut and hack
 my day so wretchedly into small pieces!" -- Plautus, 200 BC



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