best CPU for Linux?

best CPU for Linux?

Post by Tim » Wed, 05 Feb 1997 04:00:00



I am about to purchase a new computer and would like some feedback on a
particular issue... I can afford either a 200mHz MMX Pentium or a 200mHz
Pentium Pro --> which would offer the best performance under [Red Hat
4.1] Linux? (I have heard, perhaps erroneously, that there is a
performance hit when running Linux on a PPro. I find this strange in
that the PPro is optimized for 32-bit code and Linux is a 32-bit OS.)
Any suggestions?

Thanks!
        Tim
--
"You may force me to use Windows, but you can't make me like it!"

 
 
 

best CPU for Linux?

Post by Patrick Leu » Thu, 06 Feb 1997 04:00:00


: I am about to purchase a new computer and would like some feedback on a
: particular issue... I can afford either a 200mHz MMX Pentium or a 200mHz
: Pentium Pro --> which would offer the best performance under [Red Hat
: 4.1] Linux? (I have heard, perhaps erroneously, that there is a
: performance hit when running Linux on a PPro. I find this strange in
: that the PPro is optimized for 32-bit code and Linux is a 32-bit OS.)
: Any suggestions?

I do not know for certain if that's true.
However, I do not think that the CPU is the most important for
performance on any UN*X OS.  
I think the amount of RAM and hard disk space will have more impact
on the performance.  So, I recommend you to spend more money to get lots of
RAM, and disk space, especially if you plan to use your Linux box
as a server.

You may want to get two harddrives, instead of one, so both can run
parallel.  I think you'll get much better performance with two 1 gig
harddrives running in parallel than one 4 gig harddrive doing all the work
alone.
It especially makes sense to use a separate harddrive for swapping and for
/tmp.  I'm thinking of getting a 100mb harddisk for only swapping alone.
That way, you'll save your good, big harddisk which contains all your apps
from wear and tear due to swapping.  

I use 16meg of RAM, on my cyrix686-133, runs just fine.
However, when I use X-win, it's still a bit sluggish.. and not super
fast ;-))

Patrick

 
 
 

best CPU for Linux?

Post by Mark Ha » Fri, 07 Feb 1997 04:00:00


: : I am about to purchase a new computer and would like some feedback on a
: : particular issue... I can afford either a 200mHz MMX Pentium or a 200mHz
: : Pentium Pro --> which would offer the best performance under [Red Hat
: : 4.1] Linux? (I have heard, perhaps erroneously, that there is a
: : performance hit when running Linux on a PPro.

definitely erroneously!  Linux runs like a dream on a P6,
and even better on more than one.  the p5/200mmx is a nice
chip, but it's _distinctly_ slower for most things.

: : I find this strange in
: : that the PPro is optimized for 32-bit code and Linux is a 32-bit OS.)

optimization is not a trivial issue.  in fact, the new mmx chips are
significantly faster for Linux than the old ones, since they're less
sensitive to how the machine code is scheduled (instruction arrangement.)
the P6 is even less sensitive, and thus faster.  this particular
difference is a result of the fact that gcc doesn't have any (!) smarts
about scheduling code for the P5.

: I think the amount of RAM and hard disk space will have more impact
: on the performance.  So, I recommend you to spend more money to get lots of
: RAM, and disk space, especially if you plan to use your Linux box
: as a server.

this doesn't really make much sense.  the ideal resource balance
will be different for any use, and vary slightly for each OS.
there's not _that_ much difference here, though.  you shouldn't
consider buying <32M for any current machine.  you should also
probably not buy anything less than a P133.

: You may want to get two harddrives, instead of one, so both can run
: parallel.  I think you'll get much better performance with two 1 gig
: harddrives running in parallel than one 4 gig harddrive doing all the work
: alone.

larger disks are cheaper, though.  and the more disks you have,
the more your exposure to failure.  it's definitely true, though,
that several disks can be made to distribute load, reduce time spent
moving the head, etc.  and even though you stand a greater chance of
seeing a disk fail, having others means that you can recover easier.

: It especially makes sense to use a separate harddrive for swapping and for
: /tmp.  I'm thinking of getting a 100mb harddisk for only swapping alone.

bad idea: such a disk will cost much more per gigabyte than a big disk.
it's best to think of swapping as a nonfatal error condition, since it
will destroy performance, no matter how you manage it.

: That way, you'll save your good, big harddisk which contains all your apps
: from wear and tear due to swapping.  

I've never seen any evidence that "wear and tear" on a disk is proportional
to how much you use it.  conventional wisdom is that power cycles, cooling
and quality of supply power are the main influences on disk life.

: I use 16meg of RAM, on my cyrix686-133, runs just fine.

16M is skimpy.

regards, mark hahn.
--

                                        http://neurocog.lrdc.pitt.edu/~hahn/