I tested on two different computers — my venerable Dell laptop and my largely MSI-powered gaming PC.

Some thoughts:

• The newest Opera 10 build on Linux does not like the SunSpider benchmark.  Understandably, it’s a benchmark put together by the WebKit browser team, but still — it performed about as bad as I’d suppose Internet Explorer would (were it to run on Linux).  I ran it twice just to make sure, and it was about 10k milliseconds each time.
• Chromium, whether it’s on Windows XP, or the pre-alpha build I’m using on Linux, is pretty damn fast.  Like scary fast.  Though, like I said, it is their own benchmark.
• Seamonkey on Linux is consistently faster than Firefox 3.1b3 on Linux.  I have no idea why, since they’re supposed to be powered by the exact same engine.
• It’s amazing how much faster an older computer (Like my Dell laptop) can feel when you use a browser that’s optimized to render JavaScript faster.  It seriously feels like an entirely different computer.
• I tried running this test in Internet Explorer 6.0 via Wine, on Ubuntu.  I figured it’s not exactly emulation (since Wine Is Not an Emulator and all), but it kept freezing on one of the “base64″ tests, and I got tired of waiting on it and killed the process.  Imagine that.

And now, the benchmark numbers, utilizing the SunSpider JavaScript benchmark (smaller numbers are better, all numbers in thousandths of a second):

Computer #1

Hardware:  Dell Laptop, Pentium 4-M 2.6 GHz, 1.5GB DDR Ram

Software:  Ubuntu 8.04 (x86)

• 10572.4ms:  Opera 10 Alpha, Build 4214
• 8435.8ms:  Flock 2.0.3
• 8171.8ms:  Firefox 3.0.8
• 5243.6ms:  Firefox 3.1 Beta 3 (Shiretoko)
• 4701.4ms:  Seamonkey 2.0 Alpha 3
• 1506.4ms:  Chromium Dev Build

Computer #2

Hardware:  MSI Mainboard, Athlon X2 2.5GHz (Brisbane), 2GB DDR2 RAM

Software:  Windows XP SP3 (x86)

• 6930.8ms:  Internet Explorer 8
• 2097.8ms:  Firefox 3.1 Beta 3
• 952.4ms:  SRWare Iron 2.0 (Chromium)