[Gllug] Fileserver hardware advice

[Mike Brodbelt]

Martin A. Brooks wrote:
> Mike Brodbelt wrote:
>>> 4) Finally, how much difference will having a 64 bit CPU make when it
>>> comes to performance?
>>
>> It'll likely make things marginally slower for the same clock. Pushing
>> 64-bit pointers around takes a bit more work. 
> 
> Now it's not often that you and I disagree, Mike.  I'm not sure we are
> disagreeing here, but I just want to make sure.

Firstly, let me say that I think any differences are, for all real world
tasks, pretty much a total non-issue.

> Where does this myth about 64 bit processing being "slow" come from?

Sun ship a 32-bit userland and a 64-bit kernel in Solaris, and advise
users to run 32-bit unless they specifically need the address space a
64-bit app provides. Third party tests seem to bear out the fact that
their contentions are accurate, at least for SPARC/Solaris:-

http://www.osnews.com/story.php?news_id=5768

Is this relevant for Linux on x86_64 - I'd want to see actual benchmarks
to be sure, but it seems likely that you'd see the same sort of thing.
Is it important - hell no.

Just for the record, I hate Sun's hideous mix of 32-bit and 64-bit apps,
it makes compilation of other stuff a nightmare, especially when third
party apps (Python) have nasty setup routines that use autoconf, but
don't actually pay attention to what's specified. Debian's pure 64-bit
environment is an infinitely preferable approach, and I wish Sun would
follow suit.

Mike
-- 
Gllug mailing list  -  Gllug at gllug.org.uk
http://lists.gllug.org.uk/mailman/listinfo/gllug