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With the advent of Mac OS X Snow Leopard, Apple's first 64-bit consumer OS, all the major web browsers (Safari, Firefox, and Chrome) have become 64-bit. What is the advantage of a 64-bit browser over a 32-bit one on Mac? Even though Windows also has 64-bit versions of their OS, most Windows users are still running browsers in 32-bit mode. I understand the need for 64-bit computing in data intensive programs like Winrar, which need bitwise manipulation, but I don't see why a browser would need 64 bits per integer.

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up vote 3 down vote accepted

The probably most important aspect is:

64-bit browser use 64-bit plugins while 32-bit browsers use 32-bit plugins.

Keeping this in mind, a 64-bit browser is both good and bad:

  • Usually, 64-bit plugins are harder to find as their 32-bit counterparts.

  • Plugins like the Java Runtime Environment let your browser perform CPU intensive and/or memory hungry tasks. The 64-bit version of JRE has access to all cores, making some tasks magnitudes faster.

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+1. And those tasks that are magnitudes faster may be invisible to all but the heaviest users. – user3463 Dec 14 '11 at 18:27
Good observation .... but I can't recall the last time I saw a Java widget running on a website :D They seem to have gone out of style. – JoJo Dec 14 '11 at 18:31
Take the applet Factorization using the Elliptic Curve Method for example. Integer factorization is very CPU intensive and highly parallelizable . – Dennis Dec 14 '11 at 18:37
@TheCompWiz : really? I recall back in college, I was still on 32-bit Windows XP and I wrote a multi-threaded ray tracer. It almost halved the running time, meaning that the multi-threading worked. – JoJo Dec 14 '11 at 18:55
@TheCompWiz That is absolutely wrong! Reasons are too numerous to list here, but for start garbage collector always has its own thread! – AndrejaKo Dec 14 '11 at 20:26

The advantage is subtle at best. Basically it means that your web browser can process very large integer values more efficiently and without conversion. There's quite a bit of number-crunching that goes on behind the scenes of the web browser. Unfortunately, to the average user... it means nothing. Any improvements you see will be minimal at best.

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Are there any benchmarks comparing a 64-bit browser running normally versus it running in 32-bit compatibility mode on Mac? (Right click dock icon > get info > check the 32-bit mode box). And let's talk about benchmarks on normal websites, not synthetic programs that purposely do bitwise manipulation. – JoJo Dec 14 '11 at 18:35

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