Martin Gregorie  wrote:
> On Tue, 01 Dec 2020 11:36:59 +0100, A. Dumas wrote:
>
> > On 01-12-2020 11:30, A. Dumas wrote:
> >> $ time /usr/bin/factor 1234567890123456789012345678901
> >> 1234567890123456789012345678901: 7742394596501 159455563099482401
> >>
> >> real    0m2,086s user    0m2,075s sys    0m0,011s
> >
> > My 7 year old iMac (3.2 GHz quad i5) is only about 8x as fast:
> >
> > $ time gfactor 1234567890123456789012345678901
> > 1234567890123456789012345678901: 7742394596501 159455563099482401
> >
> > real  0m0,257s user   0m0,248s sys    0m0,004s
> >
> > (installed via MacPorts, then 'sudo port install coreutils')
>
> Interesting: for exactly the same number to be factored I see:
>
> 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
>
> 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.
>
For what it's worth here are my figures for the factor test, though
I doubt it has much relevance to throughput when running backups.

Lenovo T470: 0.221s 0.219s 0.001s       Core i7
Desktop:     0.192s 0.191s 0.000s       Core i5, Fujitsu Esprimo
Pi 2B:       6.931s 6.924s 0.000s
Pi 4:        2.124s 2.114s 0.010s

It's interesting that my Core i5 desktop is actually a little faster
than the Core i7 Lenovo laptop as the Lenovo is newer as well and,
subjectively, often feels a little faster.

Why my Pi 2B is so much faster than yours I don't know, it's a Pi 2B
Revision 1.1.

However the real 'wow, that's a lot faster' thing for all of them was
to move from spinning disks to SSDs. (The t470 of course had one to
start with).

--
Chris Green
·

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