Re: [Qemu-devel] emulated ARM performance vs real processor ?

[Antti P Miettinen <ananaza@iki.fi>]

Julien Heyman <bidsomail@gmail.com> writes:
> Hi,
>
> I was wondering if anyone had some data regarding the relative performance of
> any given ARM board emulated in QEMU versus the real thing. Yes, I do know
> this depends a lot on the host PC running qemu, but some ballpark/example
> figures would help. Say, I emulate a 400 Mhz ARM9 processor on a Core2Duo
> laptop @ 2 Ghz, what kind of performance/timing ratio should I expect, one way
> or the other ? For example, for boot time.
> I have no idea whether the overhead of emulation is over-compensated by the
> huge processing power of the host compared to the real HW target, and by which
> factor.
>
> Regards,
> Julien
>

Taking a look at:

http://adt.cs.upb.de/quf/quf2011_proceedings.pdf

page 20 (24th page in the PDF), figure 1b, the noprof bars, I'd expect
2GHz host to be on average faster than native target. The emulation
speed depends on how core intensive vs memory intensive your workload
is. Workloads that are memory bound in the target (e.g. gzip ASCII
compression) can me emulated much faster (e.g. factor of two) than core
bound workloads (e.g. mcrypt encryption).

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