Is D the Answer to the One vs. Two Language High ,Performance Computing Dilemma?

[Russel Winder]

On Sun, 2013-08-18 at 01:59 -0400, John Joyus wrote:
> On 08/11/2013 04:22 AM, Walter Bright wrote:
> > http://elrond.informatik.tu-freiberg.de/papers/WorldComp2012/PDP3426.pdf
> 
> This article claims the "Performance [of D] is equivalent to C".
> 
> Is that true? I mean even if D reaches 90% of C's performance, I still 
> consider it great because of its productive features, but are there any 
> benchmarks done?

Not a statistically significant benchmark but an interesting data point:

C:

==================== Sequential
	pi = 3.141592653589970752
	iteration count = 1000000000
	elapse time = 8.623442

C++:

==================== Sequential
	pi = 3.14159265358997075
	iteration count = 1000000000
	elapse = 8.61212399999999967

D:

======================== pi_sequential.d
	π = 3.141592653589970752
	iteration count = 1000000000
	elapse time = 8.612256


C and C++ were compiled with GCC 4.8.1 full optimization, D was compiled
with LDC full optimization. Oh go on, let's do it with GDC as well:

======================== pi_sequential.d
	π = 3.141592653589970752
	iteration count = 1000000000
	elapse time = 8.616558


And you are going to ask about DMD aren't you :-)

======================== pi_sequential.d
	π = 3.141592653589970752
	iteration count = 1000000000
	elapse time = 9.495549

Remember this is 1 and only 1 data point and not even a sample just a
single data point. Thus only hypothesis building is allowed, no
deductions.  But I begin to believe that D is as fast as C and C++ using
GDC and LDC. DMD is not in the execution performance game.

Further fudging, the code is just one for loop.  The parallel results
are just as encouraging for D.  I will say though that std.concurrency
and std.parallelism could do with some more work. On the other hand C
has nothing like it, whilst C++ has a few options including TBB.

As I say, indicators, not statistically significant results without big
data samples and serious ANOVA.

-- 
Russel.
=============================================================================
Dr Russel Winder      t: +44 20 7585 2200   voip: sip:russel.winder at ekiga.net
41 Buckmaster Road    m: +44 7770 465 077   xmpp: russel at winder.org.uk
London SW11 1EN, UK   w: www.russel.org.uk  skype: russel_winder
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