Internet Explorer 9: what you need to know

IE9 will be faster, smoother and better at CSS

IE9 Acid test

Update: read our Hands on: IE9 review

Microsoft showed Internet Explorer 9 for the first time yesterday at its Professional Developer Conference, but a technical preview won't be available before next year (perhaps at CES 2010 in January).

Instead, Windows Senior Vice President Steven Sinofsky demonstrated the latest test version, with the Trident rendering engine running on DirectX instead of GDI - to show that IE development is still going on, and making progress on performance and support for standards.

Like Ray Ozzie at an earlier keynote, he promised that Microsoft would "make Internet Explorer the best browser for Windows and the most world class browsing experience we can develop" but he said it would be delivered "in the most responsible way" to get "a good balance between the things we know we have to do and moving the whole notion of browsing forward".

That doesn't mean canvas or SVG support, at least not at this stage. Although Microsoft is working on HTML 5 standards, Sinofsky said that's not necessarily the main focus for IE9: "There are emerging standards that are still incomplete and draft, and we want to be responsible about how we support that and don't generate a hype cycle across the board for things aren't there yet."

And while he showed IE's ACID 3 score going up from 20 in IE 6 to 32 for the test system and agreed "that's a test we need to do a better job on," the emphasis is on supporting standards like CSS and elements like selectors and rounded corners (using CSS3 border-radius) that web developers commonly use to build sites. He showed IE9 running CSS tests from the CSS3 info site and getting a rather better score.

Early days for IE9

After only three weeks of development (the time since Windows 7 shipped has been spent on planning), Sinofsky said the performance is already significantly better than IE8, showing results on the Sunspider JavaScript benchmark that are about five times better than IE8 (which was twice as fast as IE7).

It's also far closer to the JavaScript speed of the pre-release versions of Firefox, Chrome and WebKit. "This isn't just speed," Dean Hachamovitch, General Manager of the Internet Explorer team, told TechRadar. "This is speed with security, with compatibility. You can do anything fast if you do not have to be correct."

Sinofsky also pointed out that browser performance is about a lot more than JavaScript, showing a breakdown of the time taken by rendering, handling CSS and all the other things the browser does for the Excel web app and two popular news sites. Even on a script-heavy site, JavaScript took at most a third of the time needed to load the page. "By the time you get down to this kind of performance," said Sinofsky, "it's swamped by other subsystems".

IE9 GPU acceleration

IE9 will also get a big speedup from switching the Trident rendering engine from running on the now-elderly GDI to hardware-accelerated DirectX. "We have all this amazing new hardware," points out Hachamovitch. "There are graphics cards in notebooks that blow away what you could get on the desktop just a year ago. And what takes advantage of it? Nothing."

IE9 rendering

SMOOTHER AND FASTER: DirectX rendering makes animation and graphics move far faster and much more smoothly, plus text is much smoother and easier to read

Web designers don't have to take any changes to their code to get faster rendering with much lower CPU usage, and crisper text that animates smoothly (rendered by Direct2D and DirectWrite). Sinofsky showed a page built with the Bing API, loading maps from Bing as usual, but panning at 60 frames per second rather than the 7fps GDI managed.

Microsoft hasn't yet said whether this will only work on Windows 7 and Vista or on XP as well. "Look for more detail on this in the future," Hachamovitch told us, "but the short answer is that the better the hardware, the better the experience."

IE9 is the first browser to use DirectX, although Safari on Mac uses Quartz rendering. It's not just that hardware graphics acceleration hasn't been widespread enough to take advantage of before. "The biggest disadvantage of DirectX," says Hachamovitch, "is that it's really hard to get it right. As you saw today, there's a huge benefit but it takes a lot of work to get all of the details right – like how do controls like Flash work and what about printing?"

That means that while it makes sense for Microsoft, with the Windows-only IE, cross-platform browsers may not want to invest in development just for Windows, which could give IE9 a lead that's hard to match.


Liked this? Then check out 10 Internet Explorer 8 tips direct from Microsoft

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