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Microsoft Edge to see JavaScript boosts with Windows 10 Anniversary Update

Microsoft is adding JavaScript performance improvements to the Chakra engine behind the Edge web browser, which will be available for all Windows 10 users as part of the upcoming Anniversary Update. Members of the Windows Insider program, as always, will get to see those improvements first in preview builds.

In a blog post, Microsoft offered a couple of examples of its JavaScript improvements. One of them concerns how Edge handles small-sized functions in scripts on websites:

To optimize for this pattern especially in terms of memory consumption, Chakra has refactored the metadata format used for each function (internally referred to as FunctionBody). Based on data, pointers in FunctionBody that point to rarely used information have been moved to a dynamic auxiliary structure and will not be instantiated and consume memory unless necessary. A good example is the asm.js related data which is not applicable for most functions. Most of the 32-bit counters in FunctionBody were also observed to hardly have values over 256, such as the variable count or object literal count within a function. Thus these counters have been replaced by a compact structure that uses a single byte for each counter and can be promoted to full 32-bit if needed. Combined with a good number of functions, these seemingly subtle optimizations can make a big difference in reducing memory overhead.


While Microsoft admits it doesn't care much for synthetic JavaScript benchmark tests, it did use two of them (Octane 2.0 and Jetstream 1.1) to show that its Chakra improvements allow Edge to lead both Google's Chrome and Mozilla's Firefox in the final results. Microsoft says that even more JavaScript improvements will be added to Edge in the summer.

  • I'm using Edge for 4 months. Just uninstalled all other browsers.
    IE is enough to use governmental, java etc. based websites. Edge is great for all other things. Really, great.
  • Yep
  • With Adblock of course.
  • Try Edge on, then try Chrome and FF both WITHOUT ad-blockers.  You will see Edge still have a way to go. 
  • Nope edge still dont have TPL
  • What are you talking about?  Care to explain?
  • Tracking Protection Lists.  A way you could ad-block in IE. With the Anniversary Edition we get extensions which are more capable than TPL...   one could be written to be TPL exactly if someone wanted. So not long until Jorge has no reason to complain. 
  • Ahh that makes far more sense!  My brain was still in developer land.  I was thinking he was talking about Task Parallel Library (TPL) I thought he was trying to claim that Edge only ran in a single thread. 
  • Slightly related to this article and your mention of threads... I think async javascript tests will start to show up iPhones in benchmarks.  Javascript (not Edge) is historically very single-threaded in exection but with newer async capabilities added to the language, tests yet to be written that are optimized using async processing will show up the dual core aspect of the iPhone. - 4/8 core Android/Windows phones will finally benchmark much higher in a year or two.  Of course perhaps Apple will bring more cores by then too.
  • The reason to complain is that one day IE11 support is gonna end one day and then force move to Edge,IE11 is the lower Ram Leaker for old graced computers that depend on personalised list (not adblock) Microsoft still focusing on new stuff but forgetting old ones.
  • currently edge looses with adblock extension agains ie with tpl on heavy ad sites Anyway, there are other things to complain, i can translate through right click and translate in ie...edge? Nope i cant translate just a text artefact and we will see if extensions are able to archive this, on other browsers i didnt see such functionality through extension so i dont expect those on edge.
  • If only developer tools would be better I could completely stop using opera...
  • What's the tablet in the picture? I think I need one...
  • Microsoft Surface Pro 3
  • Cool cool cool. Edge ie cool again
  • I thought MS had a mde a big deal about splitting Edge from the OS. So it could be updated independently. Is that coming, where Edge updates will be done separate from OS updates? It seems that Edge updates are only coming with new builds...or I could have been misreading the release notes.
  • It is probably due to some of the features that the updated edge needs requires features from the anniversery update.  Once those are in place then they can start doing updates independently.  That is just a guess on my part though... 
  • Edge is two chunks - the browser shell (Edge) and an OS engine (EdgeHTML).  The OS level engine is shared between apps that anyone can write and provides HTML and javascript as a globally usable module.  The browser shell is an app but is a system installed one.  I'd expect that to at least change to a store distributed one even if EdgeHTML remains an OS upgrade item, but I don't know if that's happened yet.
  • java script breaks on some webpages in edge ... buttons and menus that don't work etc ... i use squarespace and there are some themes i cant use because the menuing fails to function on edge.
  • Feedback hub is a wonderful place for you
  • I'm Using Edge from Day 1 and now it is my only browser. Microsoft Edge is Fast, Secure and Reliable.