Holy fucking shit, the IE team has been pulling some overtime. IE9 is officially far more interesting and progressive than both Firefox 3 and 4 combined.
Only thing I wish they'd do is move the address bar up and the tabs down, or vice versa. Or at least give us a means to do that.
But major credit is due; between the sheer speed of that motherfucker (started up Chrome-fast, no joke), the silky smooth scrolling that it manages thanks to its new hardware acceleration, and its amazing progress that the IE team made in terms of standards compliance, I think Trident just about has enough fuel to dethrone Mozilla in the Windows world in terms of rendering engine quality and performance. IE8 was a good step forward; IE9 is just a miracle.
Now I need to give it a whirl on a sub-standard platform. Say, my laptop.
Edit: FYI, here's the error listing that I get in IE9:
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Message from webpage
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Failed 5 tests.
Test 26 passed, but took 577ms (less than 30fps)
Test 69 passed, but took 2 attempts (less than perfect).
Test 75 failed: Object doesn't support this property or method
Test 76 failed: expected '0' but got '100' - Incorrect animVal value after svg animation.
Test 77 failed: Not implemented
Test 78 failed: expected '90' but got '1.9237771034240722' - getRotationOfChar(0) failed.
Test 79 failed: Not implemented
Total elapsed time: 2.47s
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OK
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The only time that the test really stalls for a perceivable length of time on my system is test 26, and the length of the stall varies. Total elapsed time is anywhere from around 1.4s to 2.5s. It's not quite as smooth as Chrome (which gets a perfect score on my system in both performance and, of course, rendering) but performs about as smoothly as Firefox 3.6.9 stable.
The only rendering error is that the shadow under the "Acid3" text is not displayed and, of course, the blue mark isn't completely blue due to the failed tests.
Edit: Here's a SunSpider benchmark:
http://www.favbrowser.com/ie9-platform-preview-4-beats-safari-5-acid3-95100/. IE9 platform preview 4 (which is what the beta is based on) kills Firefox 3 and 4 in JavaScript performance, edges out Safari, and closes in on Chrome.
The browser wars just got a little bit more exciting, I think.
Of course, real world use is far different than synthetic benchmarks. So far, with my limited interaction with IE9, it definitely feels far less clunky than IE8. I'm definitely going to have to test it on lower-end hardware to get a good idea of how well it's going to run.
Edit: Just loaded IE9 on my laptop and tried out a few demos. My laptop's GPU doesn't support IE9's GPU acceleration, so we're stuck with software rendering here.
Overall performance feels closer to Firefox than IE8. Firefox was fairly smooth with a bit of choppiness on certain sites with this system and IE8 just stuttered every few lines. Definitely a marked improvement over IE8. Both browsers still fall short of Chrome, which somehow manages to allow this system to scroll quickly and smoothly despite my dumb ass turning Aero on with only a RADEON X300.
I went over a few demos from Microsoft's IE test site to compare the speed of Chrome, IE, and Firefox.
In the pinball demo available on Microsoft's site, Chrome ran consistently fast, even with tons of balls on the screen. IE9 ran at a consistently slow speed, pulling maybe 10-15fps and staying roughly around there...hard to say whether it's the JavaScript engine or the rendering engine at fault there, though I'm guessing that it's the former struggling with the physics engine. Firefox 3.6 was definitely faster than IE9, but it behaved far worse from a user perspective, going back and forth between sluggish to zippy as the rendering engine failed to keep up with the JavaScript engine. If I had to guess (there's no framerate counter on the site) Firefox was going back and forth between 15fps and 45fps rapidly, which made me want to shoot myself. Firefox 4 was slower than Firefox 3.6 (!!) but held a steady framerate. It was slightly faster than IE, but it certainly wasn't a speed demon.
Another demo, the "speed read" one, showed a very different set of results. IE9 was able to maintain 2-3 fps by drawing one frame every ~400ms. Chrome stayed at a whopping 0fps because each frame too 1150ms to draw. Firefox 3.6 wound up in the middle at 750ms a frame, but I disqualified it because it didn't actually draw anything, so that doesn't really count. Firefox 4 not only actually rendered the animations (WOW) but its speed matched IE9 on my system.
Next demo I tried was the "flying images" demo, using the "all browser" setting with 36 images and the mouse cursor kept to the far left side at the vertical center of the page. IE9 stayed within a range of 8-11fps, averaging 10fps. Chrome pulled off 13-14fps, averaging 14fps. Firefox 3.6 managed 5-7fps, averaging at 6fps. Firefox 4 rendered a tad slower than 3.6, managing 4-6fps and averaging 5fps.
Next up is the EMCAScript5 Breakout demo. There was no framerate counter on it so I'm pretty much going based on my observations. IE maintained a fairly consistant framerate, with smooth movement from all three balls. Chrome started out extremely choppy, smoothing out as more blocks disappeared, then exceeded IE9's performance at the very end of the test. Firefox 3.6 does not have EMCAScript5 support (which is understandable, seeing as it was released a month after it was published). Firefox 4 performed identically to IE, smoothly animating the balls and maintaining a steady framerate.
And my final test for the night is the IE Beatz test. It's basically an HTML5-powered drum sequencer with some basic fullscreen graphical effects. IE managed a "score" (the beats per second that the JavaScript tracker is able to maintain multiplied by the framerate that the render can maintain -- the higher the better, obviously) of 280-300, Chrome managed a score of 20-30, and neither version of Firefox could run it because it can't natively play MP3s (perfectly understandable due to the patent issues).
I'm sure that the Microsoft demos are probably more intended for IE9 than other browsers, but given how far performance drifts back and forth, particularly between IE and Chrome, it seems like they are probably fairly reasonable tests in general.
In conclusion, I think it's safe to say that, despite IE beating Chrome in a few instances, Chrome is quite a bit faster overall. Firefox 3.6 and 4.0 were an odd pair. Firefox 4.0 was very close to IE9 in terms of speed and performance, though 3.6 did edge its younger brother out in a few tests.
It's also very telling that Chrome 6 -- a stable release -- overall managed to outperform both of those cutting edge, beta browsers. It's even more telling that the Internet Explorer team was not only able to catch up with, but in some cases even beat the Mozilla team in just a year and a half (IE8 was certainly no threat for Firefox 3.0 when it was released; IE9 will most
definitely be a threat to Firefox 4.0). I hope for Microsoft's sake that they keep the IE team going in full swing (I remember hearing that the reason IE suffered so badly through versions 6 and 7 was because the IE team was essentially turned into a skeleton crew) and continue to crank out quality releases. If they manage that, IE10 could very very well give Chrome a run for its money. If development continues at its current feverish pace, by the time IE9 is released it could very well end up being one of the best browsers in the Windows world.