The team's explanation: Right now, the performance tests
are run on a Mac, which means no IE. Also the tests rely on
a "shell" JS engine that runs in a command line. It doesn't
test browsers. We'll change that, eventually.
I do a lot of experiments around the edge of browser performance (and also regularly check other folks' demos in multiple browsers).
Benchmarks are not completely representative to "real world" performance. There are always some areas which work very well in particular browsers and areas in which some browsers are absolutely terrible.
You can get practically arbitrary order of browser performance by mixing "do-good" and "do-bad" tasks.
Subjectively, since recently Opera often feels faster than Chrome [1].
Not always, it's maybe 50/50 split, sometimes Chrome is faster, but in overall subjective experience Opera feels better (by a tiny bit).
I suspect it's because Chrome excels mainly at "behind-the-scene" more numerical type of tasks, while Opera is faster at more tangible "in-your-face" things like DOM manipulation / rendering / canvas.
Also, again subjectively, Opera's performance feels better "balanced". Chrome is crazy fast in some areas (see V8 benchmark), but slow/average in others. Opera is fast almost everywhere, so it has less bottlenecks.
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[1] More objectively, from my stuff which has numerically comparable performance:
(For example, "The benchmark starts with an array of 100,000 elements and removes 20 elements for each call. After 5000 calls, the calls become no-ops, and the benchmark then times those no-ops.")
Gah, I was about to say that Opera beats Chrome at Sunspider on my machine, but then realized I was still running Chrome 5. Just upgraded. Here are the Sunspider numbers on my machine:
