I'd love to hear from Mozilla how they got the 64bit version to be faster than the 32bit version. The 64bit versions of apps tend to have to move more data, due to the increased address size. The big advantage the 64bit versions tend to have is more registers for apps, but for most real apps the increased memory pressure is a bigger deal.<p>Looking forward to Mozilla's blog on writing high performance 64bit apps. :-)
I keep reading about Firefox 7/8 and their improved memory footprints, speed, and now a 64-bit version. Firefox 6 hasn't even been released yet and it's all ready a let down.
1) Wait, they're up to Firefox 8 now? I thought I heard something about Firefox 5 coming out a couple weeks ago.<p>2) Wait, they're still mainly 32-bit? People still use 32-bit computers? Maybe that's my being a Mac user, but I don't think I have very many 32-bit apps left.
The largest benefit you can expect to get from compiling 64-bit is the ability to address more memory. Performance is a bad reason, unless you need extra floating-point precision or your problem is highly vectorized, and you just doubled the size of all your pointers, so you'll be getting more cache misses. I'm really interested in how they managed these downsides.