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Box2d Revisited

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Re: Box2d Revisited

#11

Post by joelgwebber »

evmar wrote: post #10
evmar wrote: post #8

I'm curious whether the performance varies if you used a C compiler from the last five years -- GCC 4.2.1 was released in July 2007. (I'm not claimed the author of the post is unfairly biasing the results, I'm just honestly curious.)

To answer my own question, I got: gcc 4.6.3: 3.554688 +/- 4.786550 clang trunk: 3.593750 +/- 4.798172 Chrome: 41.03515625 +/- 9.331709130062185 Which puts Chrome at about 11x these native compilers, consistent with the blog post.

FWIW, I just ran it through Clang 4.1 (the standard on XCode these days), and got roughly identical performance. I'm still compiling gcc 4.8 just to be sure, but it seems unlikely to make much of a difference.

Re: Box2d Revisited

#12

Post by mrmiller »

Interesting how JS still doesn't live up to AS3. Everyone always discredits Flash... but if you're trying to make a Physics-based browser game, it still seems appropriate!

Re: Box2d Revisited

#13

Post by joelgwebber »

evmar wrote: post #10
evmar wrote: post #8

I'm curious whether the performance varies if you used a C compiler from the last five years -- GCC 4.2.1 was released in July 2007. (I'm not claimed the author of the post is unfairly biasing the results, I'm just honestly curious.)

To answer my own question, I got: gcc 4.6.3: 3.554688 +/- 4.786550 clang trunk: 3.593750 +/- 4.798172 Chrome: 41.03515625 +/- 9.331709130062185 Which puts Chrome at about 11x these native compilers, consistent with the blog post.

Ditto for gcc-4.8. Roughly the same (ever so slightly worse) performance.

Re: Box2d Revisited

#14

Post by cpleppert »

mrmiller wrote: post #12

Interesting how JS still doesn't live up to AS3. Everyone always discredits Flash... but if you're trying to make a Physics-based browser game, it still seems appropriate!

You could get even better performance if you directly coded against the alchemy VM instructions or used alchemy directly. This would be comparable to asm.js or coding Java against the unsafe memory operators.

Re: Box2d Revisited

#15

Post by azakai »

mrmiller wrote: post #12

Interesting how JS still doesn't live up to AS3. Everyone always discredits Flash... but if you're trying to make a Physics-based browser game, it still seems appropriate!

Well, the asm.js version of the benchmark is JS, and it outperformed AS3. Although as cpleppert said, perhaps an alchemy version for Flash would be faster than AS3, that would be interesting to see.

But, I'm not aware of an alchemy version of Box2D for Flash that is convenient to use from normal Flash (what presumably the rest of the game is written in), while for asm.js there is such a version (that is easily usable from normal JS), here's a demo

http://kripken.github.io/box2d.js/webgl_demo/box2d.html

So comparing currently usable versions of Box2D, the fastest JS one (the asm.js one) is faster than the fastest Flash one.

Re: Box2d Revisited

#16

Post by eliben »

joelgwebber wrote: post #11
evmar wrote: post #10

Earlier quoted context omitted.

To answer my own question, I got: gcc 4.6.3: 3.554688 +/- 4.786550 clang trunk: 3.593750 +/- 4.798172 Chrome: 41.03515625 +/- 9.331709130062185 Which puts Chrome at about 11x these native compilers, consistent with the blog post.

FWIW, I just ran it through Clang 4.1 (the standard on XCode these days), and got roughly identical performance. I'm still compiling gcc 4.8 just to be sure, but it seems unlikely to make much of a difference.

There's no Clang 4.1, though. You probably mean "the Clang that comes with version 4.1 of XCode"?

Clang 3.3 will be released soon.

Re: Box2d Revisited

#17

Post by joelgwebber »

eliben wrote: post #16
joelgwebber wrote: post #11

Earlier quoted context omitted.

FWIW, I just ran it through Clang 4.1 (the standard on XCode these days), and got roughly identical performance. I'm still compiling gcc 4.8 just to be sure, but it seems unlikely to make much of a difference.

There's no Clang 4.1, though. You probably mean "the Clang that comes with version 4.1 of XCode"? Clang 3.3 will be released soon.

Good point. Apple helpfully reports the rather confusing version string "Apple clang version 4.1 (tags/Apple/clang-421.11.65) (based on LLVM 3.1svn)" :P

Re: Box2d Revisited

#19

Post by dmm »

evmar wrote: post #10
evmar wrote: post #8

I'm curious whether the performance varies if you used a C compiler from the last five years -- GCC 4.2.1 was released in July 2007. (I'm not claimed the author of the post is unfairly biasing the results, I'm just honestly curious.)

To answer my own question, I got: gcc 4.6.3: 3.554688 +/- 4.786550 clang trunk: 3.593750 +/- 4.798172 Chrome: 41.03515625 +/- 9.331709130062185 Which puts Chrome at about 11x these native compilers, consistent with the blog post.

    gcc 4.8.0: 1.640625 +/- 3.703323
    clang 3.2: 1.718750 +/- 3.772718
    chrome   : 23.28515625 +/- 3.636932727324763
So chrome is about ~14x the native compilers.

Changing gcc to use -O2 instead of -O3 gets: 1.562500 +/- 3.630922.

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