[pypy-dev] PyPy 1.1 beta release
p.giarrusso at gmail.com
Wed Apr 22 04:33:32 CEST 2009
On Wed, Apr 22, 2009 at 04:17, Steven H. Rogers <steve at shrogers.com> wrote:
> No. 100% faster takes half the time.
First, PyPy takes (up to) twice the time of CPython.
Second, If A is 100% _slower_ than B, I take twice as much as your
time; but in that case, you can't infer that B takes 100% less time -
percentage sentences are not reversible like that; it takes 50% less
time than B, so I'd say it's 50% faster. Analogously (or for the same
reason), if from an amount of 100 €, you subtract 50% and you add the
50% of the result, you get 50 + 25 = 75 €.
At least, when you write "20 percent slower", you were referring to
the 0.8x factor (but I still think you should have written "PyPy can
be from 20% faster to 100% slower than CPython", to be absolutely
By linear scaling, I guess, 20% faster would mean "new runtime = 0.9
old runtime", but that doesn't make sense.
> # Steve
> Paolo Giarrusso wrote:
>> On Wed, Apr 22, 2009 at 03:51, Steven H. Rogers <steve at shrogers.com>
>>> I was able to parse the speed description, though I had to slow down to
>>> be sure I was capturing the intended meaning. Perhaps "20 percent
>>> slower to 100 percent faster" would work better.
>> Well, it's actually 20 percent faster to 100 percent slower. Also,
>> 100% faster would mean doing anything in no time :-D.
More information about the Pypy-dev