Microsoft says Edge with asm.js up to three times faster than IE11

JavaScript performance in Microsoft's upcoming Edge browser for Windows 10 will be much quicker, thanks to its usage of asm.js.

Microsoft has lifted the lid on its integration of Mozilla's asm.js optimisations into its Chakra JavaScript engine, and showed that it is up to three times quicker than Internet Explorer 11 in preliminary benchmarks.

Edge asm.js performance
(Image: Microsoft)

"With the preliminary asm.js support, Chakra and Microsoft Edge now perform more than 300 percent faster on Unity Benchmark, and around 200 percent faster on individual tests like zlib, which features in Google's Octane and Apple's Jet Stream benchmarking suites," said Abhijith Chatra, Chakra senior software engineering manager, and Gaurav Seth, Chakra principal PM manager, in a blog post.

Arriving in Microsoft's Edge browser for Windows 10, the performance improvements thanks to asm.js will also be available to Windows store apps written using HTML/CSS/JS and web views that target the EdgeHTML rendering engine in Windows 10, Seth and Chatra said.

Users who are running the Windows 10 Technical Preview are able to use asm.js via the about:flags page in Edge.

"We are not fully done yet," said Seth and Chatra. "We are working on fine tuning Chakra's pipeline for ASM.js support -- gathering data to validate if the current design approach performs well for real world asm.js payloads, understanding and addressing outstanding performance, functionality, and tooling issues etc. before enabling this feature by default."

In February, Microsoft announced that it would use asm.js in its Chakra JavaScript engine.

"Asm.js is a clear step towards enabling near-native performance for the web platform, which is why we're excited to bring it to Chakra in an upcoming release," Microsoft said at the time.