[Vm-dev] Dalvik vs. ART: Android virtual machines and the battle for better performance | Pocketnow

[Eliot Miranda]

On Thu, Dec 12, 2013 at 5:16 PM, Nicolas Cellier <
nicolas.cellier.aka.nice at gmail.com> wrote:

>
> That's completely germane, but he didn't say 100% faster, it's me that
> said twice as fast.
>

I posted a quote.  "Others say it’s closer to 100%.".  As Igor said, it's
illiterate nonsense.  I posted a jokey reply.

Speed is measurable say as number of operations per second (ops), if my
> score is 10 ops, then a 100% increase of speed => 20 ops.
> I love percents, for you can say one thing, and be sure another will be
> understood ;)
>

That's why one must use a well-defined unambiguous measure of performance:
new - old / old, hence 100% faster is at best ambiguous and at worse
meaningless.


>
>
> 2013/12/12 Eliot Miranda <eliot.miranda at gmail.com>
>
>>
>>
>>
>>
>> On Thu, Dec 12, 2013 at 2:53 PM, Nicolas Cellier <
>> nicolas.cellier.aka.nice at gmail.com> wrote:
>>
>>>
>>> But he said increase in speed, not performance.
>>>
>>
>> Same argument.  What does it mean to complete a task 100% faster?  What
>> does it mean to reach your destination 100% faster?
>>
>>
>>>
>>>
>>> 2013/12/12 Eliot Miranda <eliot.miranda at gmail.com>
>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Thu, Dec 12, 2013 at 1:23 PM, Nicolas Cellier <
>>>> nicolas.cellier.aka.nice at gmail.com> wrote:
>>>>
>>>>>
>>>>> I would interpret twice as fast, and that's only 50% rather than 100%
>>>>> reduction of execution time :)
>>>>>
>>>>
>>>> relative performance = new time - old time / old time.
>>>> 2x = -50%
>>>> 3x = -75%
>>>> etc
>>>>
>>>> -100% means new time = 0, and performance is infinite.
>>>>
>>>>
>>>>>
>>>>>
>>>>> 2013/12/12 Eliot Miranda <eliot.miranda at gmail.com>
>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Thu, Dec 12, 2013 at 1:08 PM, phil at highoctane.be <
>>>>>> phil at highoctane.be> wrote:
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> http://m.pocketnow.com/2013/11/13/dalvik-vs-art
>>>>>>>
>>>>>>
>>>>>> "The benefits? Some sources are reporting a 50% increase in speed.
>>>>>> Others say it’s closer to 100%. Many claim they’ve seen their battery life
>>>>>> increase by 25% or more!"
>>>>>>
>>>>>> Got to love those 100% speed increases.  Apps really fly when they
>>>>>> take no time at all...
>>>>>>
>>>>>> --
>>>>>> Eliot
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> best,
>>>> Eliot
>>>>
>>>>
>>>
>>>
>>
>>
>> --
>> best,
>> Eliot
>>
>>
>
>


-- 
best,
Eliot
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