As promised, here’s the first test of Mozilla’s new Firefox Minefield 3.7a5pre 64 bit.
The new x64-based browser did well and considering it is the first official version ever made and still a pre-alpha it did surprisingly good.
Here is how we tested:
We choose two popular benchmarks (V8 and Peacekeeper). Every benchmark was ran three times on every browser on the same machine (Windows 7 Professional 64bit, Intel Core(TM)2 Quad Q6600 @ 2,4 GHz, Nvidia 9800 GT, 4 GB RAM).
We then took all three results, calculated the average and compared it to the corresponding results of the opponent.
Expecting a rather weak performance of the new x64 Firefox – please remember it’s early stage in development – we were surprised.
The following diagram of the V8 benchmark shows the performance of the new Firefox 64bit in percent to it’s 32bit brother (=0, basis). Green bars indicate a better result than the 32bit version, red bars mean a worse result.

V8 Benchmark - Firefox 32 bit (base 0) vs Firefox 64bit (performance in %)
While the 7% lower CPU usage (max) isn’t very sound (x86: 29%, x64: 27%), the benefits of the new architecture are quity obvious when looking at the results of the V8 crypto benchmark. That’s a 17.5% jump compared to the 32bit version and exactly the 64-bit boost expected by Mozilla. They also hope to see improvements on speed with media-rich websites, but more of that later this article.
Since Firefox 3.7a5pre x64 is in a very early stage, it is very dispensable to discuss the weaker partial results like Splay or DeltaBlue. The over all performance is just 8.6 percent behind the x86 (32bit) version – remarkable for this early stage.
Even more stunning are the Peacekeeper results.
Futuremark Corporations versatile Benchmark resulted in the 64bit browser being on a par with the 32bit one. Only a subtle distinction of -2.4% or 3039 Points (x86) vs 2965 Points (x64) was measurable.
Including all test Peacekeeper partial results into a final score, the Firefox 64bit even wins the duel by +18.26% or 3984,5 Points (x86) vs. 4712 Points (x64).
But see the following diagram for more details:

Peacekeeper - Firefox 64bit vs 32bit, (bigger numbers are better)
You have to know, that Futurmark’s Peacekeeper doesn’t add up all partial results, because some quite modern tests are not supported by some of the other browser producer. Luckily, both Foxes master these tests so for better comparison, these were included into calculation into the mentioned final score.
Examining the diagram, one partial result comes to the viewers eye: A giant 56% performance jump for the young 64bit browser in calculating / displaying complex graphics. As mentioned before, this is the second area developers think where the most potential of 64bit browsers are.
To hardware resources:
While the differences in CPU usage were neglect-able, the RAM usage was quit out of line. While the 32bit Firefox needed a maximum of 192 MB RAM, the new 64bit Firefox used 265 MB RAM (Peacekeeper Benchmark) and even 308 MB while computing V8.
You see, on the one hand there are a few things to improve, like memory management and overall performance but especially in the results of the Peacekeeper benchmark you can recognize the high potential the new 64-bit architecture has.
Download Mozilla Firefox / Minefield 3.7a5pre 64bit for x64 systems
Download Mozilla Firefox / Minefield 3.7a5pre 32bit for x86 systems