4 ms·

1. JavaScript's speed is actually not far from Mono's now. And constantly getting closer. 2. I don't think anyone but Microsoft would support .NET bytecode in

by azakai 15y ago

1. JavaScript's speed is actually not far from Mono's now. And constantly getting closer. 2. I don't think anyone but Microsoft would support .NET bytecode in the browser, simply because Microsoft controls .NET and has patents on it. It would take a lot more to reassure other browser vendors than Microsoft's existing CPs. 3. Running dynamic languages on Mono is slow. Look at the speed of all the dynamic languages on Mono (or the JVM for that matter), and compare them to native implementations of dynamic languages, in particular JavaScript and Lua. The native implementations beat dynamic languages on Mono by a large margin, simply because .NET is a bytecode made for static languages. Of course you can say that you prefer to have static languages in the browser over dynamic ones, that's a legitimate opinion of course, but not everyone would agree. 4. Standardizing on bytecode can inhibit innovation. JavaScript doesn't have a bytecode standard, which let JS engines implement very different ways of running it (V8 doesn't have a bytecode interpreter at all, for example). Of course standardizing on syntax also inhibits innovation, just in other ways, it isn't clear which is better. 5. Static languages compiled to JavaScript (that is, that use JavaScript as their 'assembly') are getting quite fast. Some benchmarks I ran found them to be around 5X slower (on the development versions of SpiderMonkey and V8) than gcc -O3, compared to Mono which is 2.5X slower, http://syntensity.blogspot.com/2011/06/emscripten-13.html http://syntensity.blogspot.com/2011/06/emscripten-13.html 6. There is already Silverlight/Moonlight which does .NET in browsers, and it hasn't been very successful. (Of course it is a chicken and egg thing, if it were bundled in browsers it might be more popular. But the failure of Silverlight is a disincentive to add Mono to browsers nonetheless.) For all these reasons, I don't think Mono has much of a chance to be included in browsers. Most of the same arguments apply to other static-language bytecodes like NaCl.

nxn 15y ago
>> 1. JavaScript's speed is actually not far from Mono's now. And constantly getting closer. http://shootout.alioth.debian.org/u32/benchmark.php?test=all&lang=v8&lang2=csharp http://shootout.alioth.debian.org/u32/benchmark.php?test=all... <- That still looks sort of far to me. >> 3. Running dynamic languages on Mono is slow. Look at the speed of all the dynamic languages on Mono (or the JVM for that matter), and compare them to native implementations of dynamic languages, in particular JavaScript and Lua. The native implementations beat dynamic languages on Mono by a large margin, simply because .NET is a bytecode made for static languages. It's not fair to compare JavaScript, which is already approaching a limit of how fast it can go, with the speed it gets running in Mono. Why? The two implementations have a vast difference of amount of energy and resources thrown at them; had Google, Mozilla, and Microsoft wanted JS to run fast on Mono, it would run fast on Mono. Also saying that .NET is a bytecode made for static languages is kind of iffy now that the "Dynamic Language Runtime" is a part of .NET
- true_religion 15y ago
  He's wright, apart from pidigits the V8 execution is within the same order of magnitude as a Mono execution.
- azakai 15y ago
  1. The Alioth results are not necessarily final - they compare a single JS engine, and we have several fast ones now (SpiderMonkey with type inference can be significantly faster on some benchmarks, for example). Even so, the median speed there is 2X, which is fairly close. Admittably there are some bad cases though, in particular pidigits (badly written benchmark code? bug in v8?). 2. It is true that JS on Mono has had far less work done, and that the DLR exists. However, the fact remains that dynamic languages are a late addition to the JVM/.NET model. For example, one very important thing for dynamic language performance is PICs, and to my knowledge there is no good example of fast PIC performance on the JVM or CLR. In fact, we don't even have a good example of a generic virtual machine that can run multiple dynamic languages fast (Parrot exists, but is not that fast) - all the fast dynamic language implementations are language-specific, so it shouldn't surprise us that VMs built for static languages don't do that well either.
  - nxn 15y ago
    In my opinion it makes no difference that we have several fast engines where some are faster at some things than others. When executing in the browser you don't get to pick and chose how and where your application will be executed. If you run into performance problems on one of the engines you can: A) dismiss a subset of your users and their performance problems, telling them to use a browser with a faster engine (they wont), B) only allow certain functionality based on a user agent string, or C) limit your applications scope to one that runs suitably in the slowest of the engines you're willing to support. In essence, if the application runs great in browser A but chokes in browser B, are you willing to say bye bye to your A users to take advantage of performance gains on B? I've been in this situation, and in my experience I've always had to look away from the faster browser rather than the user. Outside the browser you probably have a little more freedom, but it's not like you get to pick and chose in the style of "Oh, I'll execute this function in V8 since it does this faster, and that function in SpiderMonkey since it's faster there". For this reason, I don't think the fact Alioth only has measures for one engine would make a significant difference in the overall comparison. You'd be, for the most part, gaining performance in one place by sacrificing in another. Anyway, in my personal experience, I've ran into performance problems in JS a lot more often than with C#. I also have to go through a lot more tedious practices to ensure my JS code runs as fast as it can, where as in C# Some.lookup.with.lots.of.dots.does.not.scare.me(). That's why your claim sort of surprised me. Then again, the last serious JS performance problem I had was 6 months ago (before FF4), so maybe a lot has happened in those 6 months. By the way, I'm not too informed on how type inference is done in SpiderMonkey, so I may be completely wrong in mentioning this, but it sounds like they're trying to speed up a dynamic language by mimicking static typing. If that's how far they're going to improve performance, maybe soon enough JavaScript will in fact sit better in the Mono/.NET/JVM?

by azakai 15y ago

nxn 15y ago

>> 1. JavaScript's speed is actually not far from Mono's now. And constantly getting closer. http://shootout.alioth.debian.org/u32/benchmark.php?test=all&lang=v8&lang2=csharp http://shootout.alioth.debian.org/u32/benchmark.php?test=all... <- That still looks sort of far to me. >> 3. Running dynamic languages on Mono is slow. Look at the speed of all the dynamic languages on Mono (or the JVM for that matter), and compare them to native implementations of dynamic languages, in particular JavaScript and Lua. The native implementations beat dynamic languages on Mono by a large margin, simply because .NET is a bytecode made for static languages. It's not fair to compare JavaScript, which is already approaching a limit of how fast it can go, with the speed it gets running in Mono. Why? The two implementations have a vast difference of amount of energy and resources thrown at them; had Google, Mozilla, and Microsoft wanted JS to run fast on Mono, it would run fast on Mono. Also saying that .NET is a bytecode made for static languages is kind of iffy now that the "Dynamic Language Runtime" is a part of .NET

true_religion 15y ago
He's wright, apart from pidigits the V8 execution is within the same order of magnitude as a Mono execution.
azakai 15y ago
1. The Alioth results are not necessarily final - they compare a single JS engine, and we have several fast ones now (SpiderMonkey with type inference can be significantly faster on some benchmarks, for example). Even so, the median speed there is 2X, which is fairly close. Admittably there are some bad cases though, in particular pidigits (badly written benchmark code? bug in v8?). 2. It is true that JS on Mono has had far less work done, and that the DLR exists. However, the fact remains that dynamic languages are a late addition to the JVM/.NET model. For example, one very important thing for dynamic language performance is PICs, and to my knowledge there is no good example of fast PIC performance on the JVM or CLR. In fact, we don't even have a good example of a generic virtual machine that can run multiple dynamic languages fast (Parrot exists, but is not that fast) - all the fast dynamic language implementations are language-specific, so it shouldn't surprise us that VMs built for static languages don't do that well either.
- nxn 15y ago
  In my opinion it makes no difference that we have several fast engines where some are faster at some things than others. When executing in the browser you don't get to pick and chose how and where your application will be executed. If you run into performance problems on one of the engines you can: A) dismiss a subset of your users and their performance problems, telling them to use a browser with a faster engine (they wont), B) only allow certain functionality based on a user agent string, or C) limit your applications scope to one that runs suitably in the slowest of the engines you're willing to support. In essence, if the application runs great in browser A but chokes in browser B, are you willing to say bye bye to your A users to take advantage of performance gains on B? I've been in this situation, and in my experience I've always had to look away from the faster browser rather than the user. Outside the browser you probably have a little more freedom, but it's not like you get to pick and chose in the style of "Oh, I'll execute this function in V8 since it does this faster, and that function in SpiderMonkey since it's faster there". For this reason, I don't think the fact Alioth only has measures for one engine would make a significant difference in the overall comparison. You'd be, for the most part, gaining performance in one place by sacrificing in another. Anyway, in my personal experience, I've ran into performance problems in JS a lot more often than with C#. I also have to go through a lot more tedious practices to ensure my JS code runs as fast as it can, where as in C# Some.lookup.with.lots.of.dots.does.not.scare.me(). That's why your claim sort of surprised me. Then again, the last serious JS performance problem I had was 6 months ago (before FF4), so maybe a lot has happened in those 6 months. By the way, I'm not too informed on how type inference is done in SpiderMonkey, so I may be completely wrong in mentioning this, but it sounds like they're trying to speed up a dynamic language by mimicking static typing. If that's how far they're going to improve performance, maybe soon enough JavaScript will in fact sit better in the Mono/.NET/JVM?