One area where D has the edge

[Paulo Pinto via Digitalmars-d]

On Monday, 26 January 2015 at 22:12:24 UTC, Laeeth Isharc wrote:
> " If Java consumes 15% more power doing it, does
>>> it matter on a PC? Most people don't dare. Does it matter for 
>>> small-scale server environments? Maybe not. Does it matter 
>>> when you deploy Hadoop on a 10,000 node cluster, and the 
>>> holistic inefficiency (multiple things running concurrently) 
>>> goes to 30%? Ask the people who sign the checks for the power 
>>> bill. Unfortunately, inefficiency scales really well.
>>
>> No, Java does not consume 15% doing it, because there isn't 
>> just one implementation of Java compilers.
>>
>> Most comercial JVMs do offer the capability of ahead of time 
>> native code compilation or JIT caches.
>>
>> So when those 15% really matter, enterprises do shell out the 
>> money for such JVMs.
>>
>> Oracle commercial JVM and the OpenJDK are just the reference 
>> implementation.
>
> Thanks for the colour.  (For clarity, the content from the link 
> wasn't by me, and I meant the general gist rather than the 
> details).  How do commercial JVMs rate in terms of memory usage 
> against thoughtful native (D) code implementations?  Is the 
> basic point mistaken?


So far I just dabbled in D, because our customers choose the 
platforms, not we.

However, these are the kind of tools you get to analyse 
performance in commercial JVMs,

http://www.oracle.com/technetwork/java/javaseproducts/mission-control/java-mission-control-1998576.html

http://www.oracle.com/technetwork/server-storage/solarisstudio/features/performance-analyzer-2292312.html

Just providing the examples from Oracle, other vendors have 
similar tools.

With them, you can drill down the whole JVM and interactions at 
the OS level and find performance bottlecks all the way down to 
generated Assembly code.


As for memory usage, Atego JVMs run in quite memory constrained 
devices.

Here is the tiniest of them, 
http://www.atego.com/products/atego-perc-ultra/

--
Paulo