C, Java and Javascript numeric benchmark and a big surprise

In older posts on this blog I showed that Java’s performance can come pretty close to C – at least for simple numeric benchmarks. Android’s Dalvik VM is often blamed for its bad performance, though things have improved since the introduction of a JIT. With all that HTML5 vs. native debate and the ongoing Javascript hype I though it would be cool to run some benchmarks and compare the performance of Java, Javascript and C on my notebook, an iPhone 4S and a Google Nexus 7.

I decided to run a mandelbrot benchmark first. This time I wanted to see a nice colored mandelbrot set and found a Javascript version on http://www.atopon.org/mandel/# . I decided to bring that source code to Java and C (no SSE intrinsics, just plain C code to support all platforms). Here are the results showing the duration in milliseconds for each language and platform:Mandelbrot_CJJS

  • On the MacBook Pro the performance is within a narrow range. C wins with 19 msecs, Java is second with 21 msecs and Javascript is amazingly quick with 22 msecs.
  • On the iPhone the Javascript Nitro Engine takes 113% more time that the C version. Nevertheless almost factor 2 isn’t too bad for a dynamic language.
  • The most surprising result was on the Google Nexus 7. C was fastest, the Java code on the Davlik VM was 144% slower and the V8 Javascript engine achieved to beat the Dalvik VM significantly. The first computation was 65% slower and after that warm up subsequent computations were only 42% slower than C. Once again: V8 is much faster than Dalvik and easily within a range of 2 to C!

A single benchmark doesn’t prove anything, so why not add another well known benchmark. I took NBody (as I always did on this blog ;-)).

The results for NBody confirmed those results. For C I took the fastest plain C implementation from the Computer Language Benchmarks Game. Once again the y-axis shows the duration (this time in seconds).NBody_CJJS

  • On the MacBook Pro Javascript was 44% slower than C (Java only 1.5%).
  • The Javascript Nitro VM on my iPhone 4S was 99% slower than C.
  • On the Nexus 7 there’s once again the same image: Java is 106% slower than C, Javascript only 43%. Amazing.

For simple numeric benchmarks the performance of Javascript is simply astonishing. On the MacBook Pro Javascript is incredibly close to the performance of C and Java. On the iPhone Javascript was within a range of factor 2.1. For me it was very surprising to see V8 on Android being able to beat Java on the Davlik VM by a large margin.

Fine print:

  • Slower and faster usually cause headaches in benchmarks (There a nice paper about that http://hal.inria.fr/docs/00/73/92/37/PDF/percentfaster-techreport.pdf). I sticked with the elapsed time, such that e.g. 42% slower means that the factor of the durations was 1.42.
  • On the MacBook Pro C was compiled with clang using -O3 -fomit-frame-pointer -march=native -mfpmath=sse -msse3 for x64. Java was Oracle Hotspot 1.8.0-ea-b87 on 64 bit (thus C2 aka Server Hotspot). Chrome was 28.0.1493.0, but the 32 bit version. I tried to compile V8 myself, but both the x86 and x64 custom built V8 were significantly slower than Chrome so I stick with Chrome.
  • On the iPhone I used a release configuration using clang with (among others) -O3 -arch armv7
  • The Google Nexus 7 runs Android 4.2.2, Chrome 26.0.1410.58. C was compiled with -march=armv6 -marm -mfloat-abi=softfp -mfpu=vfp -O3.

6 thoughts on “C, Java and Javascript numeric benchmark and a big surprise

  1. Thanks for spotting hat typo. Enabling SSE is fine (Java and V8 use it on the desktop too).

  2. Could you show us the C and Java versions of the source? How did you calculate the elapsed time (e.g. does the Java version include JVM startup time?).

  3. You can download the source code here.
    Yes, startup time is fully included for both V8 and Java. The reason for this is that a user won’t care if the code is AOT compiled or with a profiling JIT, so they better be fast enough the first run or “native” languages will win (especially for mobile devices).

  4. Dalvik might not be an official (which means Oracle) or certified Java TM virtual machine (this is why I even put “Java” in quotation marks when I talked about the Dalvik VM), but for sure the code it runs was written in the Java programming language. And it even is THE way to run Java code on Android.
    And it’s interesting to compare C (static typing and ahead of time compilation) with Java (static typing, JIT compiler) and Javascript (dynamic and weak typing, JIT compiler).

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