On Tue, 01 Dec 2020 13:20:52 +0000, Theo wrote:

> Martin Gregorie  wrote:
>> System       Real    User    Sys     CPU ======
>> Lenovo T420   0.254s  0,252s 0.002s  1.9GHz Core i5 Lenovo R61i
>> 0.702s  0.693s 0.006s  1.6GHz Core Duo Whitebox PC   0.321s  0.314s
>> 0.004s  1.0GHz AMC Dual Athlon RPI 2B       21.995s 11.496s 0.040s
>
> Bear in mind that you're probably running a 32 bit RPi OS (on the Pi 2
> you will be), and the PCs are probably running 64 bit binaries.  That'll
> make a large difference to the speed of the arithmetic for this test.
>
> Also to note that GNU Factor can be compiled to use libgmp, which has
> custom assembler implementations of key functions.  It appears the one
> on Ubuntu 18.04 isn't compiled that way, but that could make a large
> difference in performance if different OSes are compiled different ways
> (as well as the ARM v x86 comparison being different)
>
> I don't think it's a particularly good benchmark to compare across
> architectures.  And of course it's only single threaded.
>
>> I'd been wondering whether an RP14B would be a good replacement for the
>> old AMD whitebox, but it looks as if a some sort of mini-ITX system
>> would be a better bet because I do all backups via rsync to a removable
>> USB drive connected to the old AMD system, and to do what I need it to
>> do, a replacement would need a minimum of 4 USB ports plus SATA and a
>> VGA- capable display port.
>
> That sounds like what you care about is I/O performance rather than CPU
> performance.  Also bear in mind that mini ITXes are (mostly) a
> completely different power class from the RPi.  Horses for courses.
>
Indeed the AMD box doesn't do a lot: it runs my local website (apache)
plus my getmail/spamassassin/postfix/dovecot mail handling chain plus a
couple of Java/PostgreSQL applications  that do their heavy lifting at
night along with an rsnapshot disk backup. The only time it gets a decent
workout is once a week when every system that is backed up gets rsynced
to a USB drive attached to the AMD box immediately before a software
update. So, as you thought, I care more about its i/o throughput than its
CPU performance.




--
--
Martin    | martin at
Gregorie  | gregorie dot org

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