[pypy-dev] PyPy 1.1 beta release
Carl Friedrich Bolz
cfbolz at gmx.de
Tue Apr 21 09:50:24 CEST 2009
Niko Matsakis wrote:
> On Apr 20, 2009, at 8:36 PM, Jacob Hallén wrote:
>
>> I think this formulation is a bit confusing. It is not our speed
>> that is 0.8-2x CPython, it is our performance relative to CPython
>> that is between 0.8 and 2, with 0.8 meaning that we are faster than
>> CPython on those benchmarks, and 2 meaning that we need twice the
>> time to run the benchmark.
>
> Maybe I am a bit confused, but I don't see a difference between those
> two things?
>
> i.e., if the speed is 0.8x CPython, to me that means that it runs in
> 80% of CPython's time (i.e., faster), whereas 2x CPython would be
> twice as much time.
>
> In any case, I agree that the second formulation is phrased more
> clearly, just curious if my understanding of 0.8x is flawed.
>
Hi Niko,
FWIW, that's the reasoning we had when we wrote the thing. However, we
keep having this discussion every time we write something about
performance, so I guess it's not as clear as you and me think :-).
Carl Friedrich
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