5 ms·

I ran the demo in chrome not that long after it was released and recall the frame rate being almost as good as in the recommended firefox nightly builds. There

I ran the demo in chrome not that long after it was released and recall the frame rate being almost as good as in the recommended firefox nightly builds. There was some visual weirdness (polygons being missing/transparent). I expect Epic's announcement is more about these glitches being resolved then performance increases. Mozilla's is pure spin.

jlongster 13y ago
That's not true, if you ran it in Chrome it was extremely laggy, but you must have caught it after they implemented a lot of asm.js optimizations. You can see when they focused on asm.js-style code here in these graphs: http://arewefastyet.com/#machine=11&view=breakdown&suite=asmjs-apps http://arewefastyet.com/#machine=11&view=breakdown&suite=asm.... Just look at the drop off of the green line!
- mraleph 13y ago
  I also suggest zooming into those graphs to see which changes lead to drops (at least those that are currently visible). Then you could try to explain people what asm.js specific is in changes like: https://code.google.com/p/v8/source/detail?r=14658 https://code.google.com/p/v8/source/detail?r=14658 and https://code.google.com/p/v8/source/detail?r=15147 https://code.google.com/p/v8/source/detail?r=15147 [hint: nothing, they have more to do with how Emscripten has a tendency to produce extremely big functions which no human would write, and JIT has to accomodate for that to hit them in correct moment and not give up on them. Once it hits them however the optimizations that were there for ages, optimizations purely based on JavaScript semantics, start doing what they are intended to do --- make JavaScript run fast]
bad_user 13y ago
Not sure what computer you ran the demo on, but the Unreal Engine demo on top of Chrome was unusable on my laptop (talking about 2-5 fps), whereas in Firefox it was extremely smooth and this was when Firefox 22 was released (so it was the stable release, not the nightlies). EDIT: I just ran that demo in Chrome, on the same computer as before and it did improve a lot (getting 50-60 fps in full screen HD), though it still seems smoother in Firefox. Competition is great.

jlongster 13y ago

That's not true, if you ran it in Chrome it was extremely laggy, but you must have caught it after they implemented a lot of asm.js optimizations. You can see when they focused on asm.js-style code here in these graphs: http://arewefastyet.com/#machine=11&view=breakdown&suite=asmjs-apps http://arewefastyet.com/#machine=11&view=breakdown&suite=asm.... Just look at the drop off of the green line!

mraleph 13y ago
I also suggest zooming into those graphs to see which changes lead to drops (at least those that are currently visible). Then you could try to explain people what asm.js specific is in changes like: https://code.google.com/p/v8/source/detail?r=14658 https://code.google.com/p/v8/source/detail?r=14658 and https://code.google.com/p/v8/source/detail?r=15147 https://code.google.com/p/v8/source/detail?r=15147 [hint: nothing, they have more to do with how Emscripten has a tendency to produce extremely big functions which no human would write, and JIT has to accomodate for that to hit them in correct moment and not give up on them. Once it hits them however the optimizations that were there for ages, optimizations purely based on JavaScript semantics, start doing what they are intended to do --- make JavaScript run fast]

bad_user 13y ago

Not sure what computer you ran the demo on, but the Unreal Engine demo on top of Chrome was unusable on my laptop (talking about 2-5 fps), whereas in Firefox it was extremely smooth and this was when Firefox 22 was released (so it was the stable release, not the nightlies). EDIT: I just ran that demo in Chrome, on the same computer as before and it did improve a lot (getting 50-60 fps in full screen HD), though it still seems smoother in Firefox. Competition is great.