Performance and Compatibility

Speed was the reason so many turned away from Internet Explorer (and Firefox) to Google's Chrome. IE8 trailed Chrome on JavaScript benchmarks by orders of magnitude. IE9 rights that, with top performance among all current browsers on some tests. It also adds speed through its innovative hardware acceleration, which works for more than just 3D graphics. By precompiling JavaScript on a second CPU core, the browser can take performance up a notch.

In one measure of performance that's important to everyone—the time it takes to start up the browser—IE9 has nothing to worry about: I tested the big three browsers on a weak netbook with a 1.66GHz Atom CPU and 1GB RAM running 32-bit Windows 7. After a reboot, IE9 took 3.5 seconds to start up, Chrome's 2.6 took seconds, and Firefox 4 took 6 seconds. Closing and restarting the browser without a reboot took IE9 1.1 seconds, Firefox 2.2 seconds, and Chrome .9 seconds.

IE9 now wins the SunSpider JavaScript Benchmark, with 246ms on my 2.6GHz dual core laptop, compared with 283 for Google Chrome. Microsoft has been accused of optimizing for this benchmark, but, as we'll see, the browser does well on other JavaScript measures, too (though this is the only one it wins). It would be naïve to think that browser makers don't optimize their engines to do well on these widely cited tests, too. To get the following results, I shut down any unessential processes for three averaged test runs on a Core 2 Duo 2.6GHz Windows 7 (32-bit) laptop with 3GB of DDR2 memory:
Browser SunSpider 0.9.1 Score in ms
(lower is better)
Internet Explorer 9 246
Opera 11 277
Firefox 4 RC 280
Google Chrome 10 283
Safari 5 357
Firefox 3.6 853
Internet Explorer 8 4020
On Firefox maker Mozilla's Kraken, another JavaScript benchmark, IE9's final release makes big improvements over its beta, but Chrome 10 improved even more. Mozilla contends that this benchmark reflects more realistic workloads than the other two JavaScript benchmarks, and it takes quite a bit longer to run.

Browser Mozilla Kraken 1.0 Score in ms
(lower is better)
Firefox 4 RC 6760
Google Chrome 10 8171
Opera 11 12413
Internet Explorer 9 15050
Safari 5 17603
Firefox 3.6 25969
IE9 also shows a huge improvement over IE8 in its performance on Google's V8 benchmark, though it still significantly trails the benchmark maker's browser, and Firefox 4 RC. Google's Chromium blog claims that the benchmark is designed to "capture the areas in which a JavaScript engine has to perform well to support the well-structured, maintainable, and high-performance Web applications of tomorrow." Here are my results on the same machine:

Browser Google V8 (v.6) Score
(higher is better)
Google Chrome 10 8305
Firefox 4 RC 3751
Opera 11 3527
Safari 5 2567
Internet Explorer 9 2360
Firefox 3.6 553
Internet Explorer 8 128

These script speed tests measure just a small piece of performance, though, and in normal browsing, I was hard pressed to see a difference between Chrome, IE, and Firefox 4 RC.

To measure a different kind of performance, Microsoft engineers have authored tests on the IETestdrive site. These demonstrate IE9's graphics hardware acceleration. One I like to use is Psychedelic Browsing, which displays a spinning color wheel while playing spacy sounds and reports a result in RPM. While no one touches IE9, thanks to its DirectX hardware acceleration, Firefox 4 beta does thump Chrome 9, though Firefox doesn't play the sound as the test requires and Chrome does. Here were my results for this test:

Browser Psychedelic Browsing
RPM (higher is better)
Internet Explorer 9 3911 (correct sound)
Firefox 4 RC 2830 (no sound)
Google Chrome 10 98 (correct sound)
Opera 11 82 (no sound)
Safari 5 83 (no sound)
Firefox 3.6 19 (no sound)

One final test of hardware acceleration comes from Mozilla, its Hardware Acceleration Stress test, which spins a spiral of photos in the browser window and reports a score in frames per second. This test showed the two browsers furthest along in implementing hardware acceleration to good advantage (note the benchmark no longer reports frame rates over 60FPS, as that's the limit of standard LCDs):

Browser Mozilla Hardware Acceleration Stress Test
FPS (higher is better)
Firefox 4 RC 60+
Internet Explorer 9 60+
Opera 11 17
Google Chrome 10 17
Firefox 3.6 8
Safari 5 3

IE8 wouldn't run the test. The upshot of all this is that IE no longer needs to hang its head when it comes to browsing speed, and in some circumstances it's the fastest choice. Still, for day-to-day browsing, most won't notice a difference between Chrome, Firefox 4 RC, and IE9.