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

[Nicolas Cellier]

If you want to know if it's the VM, I'd say just try Cuis.


2013/12/13 phil at highoctane.be <phil at highoctane.be>

>
> Google wants to beat the speed of iOS. iOS uses native code and
> Objective-C highly optimized dispatch loop. So, with a less powerful piece
> of hardware, Apple devices trounce Android ones when it comes to smoothness
> of animations, battery etc.
>
> As Android uses the Dalvik VM, the only way to get as speedy as iOS is to
> go as close to native as possible.
>
> We are talking 60 fps for a lot of pixels these days. My Nexus 7 with
> 4.4.2 still feels laggy compared to my iPad2. That is due to the whole
> VM/Java thing. iPad2 is 2-core, Nexus 7 is 4-core and with a NVidia
> graphics chip.
>
> AOT is working very well when it comes to Java code (well, Android Dalvik
> bytecode here).
> http://en.wikipedia.org/wiki/AOT_compiler
>
> AOT is getting a lot of traction these days. LLVM also has this.
>
> So, why care about 50% or 100%, the point is that it is getting faster in
> a way that affects the user perception. Which is what matters.
>
> For example, Pharo feels slow compared to Dolphin, Smalltalk/X etc. Maybe
> the VM is of equivalent speed. Not the user experience.
>
> Phil
>
> On Fri, Dec 13, 2013 at 12:13 AM, Igor Stasenko <siguctua at gmail.com>wrote:
>
>>
>>
>>
>>
>>  On 12 December 2013 23:57, Eliot Miranda <eliot.miranda at gmail.com>wrote:
>>
>>>
>>>
>>>
>>>
>>> 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?
>>>
>>>
>> not much apart from the author's lack of literacy :)
>>
>>
>>>
>>>>
>>>> 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 regards,
>> Igor Stasenko.
>>
>>
>
>
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