Mozilla accelerates Firefox: 3.6 alpha 1 already faster than 3.5

Feature – Mozilla recently released the first completely alpha version of Firefox 3.6, which is scheduled to replace the current version 3.5.x later this year. Planned as an incremental update, the new browser will update the Firefox layout engine “Gecko” to version 1.9.2. There are several new backend features, but Mozilla claims that version 3.6 will be much faster than version 3.5. Time to take the browser for a test drive.

Firefox 3.5 has turned into a routine maintenance product for Mozilla, with security patches dominating the update schedule. However, the next browser, code-named “Namoroka”, is already on the horizon and is expected to replace the current “Shiretoko” (v3.5) Firefox by the end of November. Referred to as Firefox.Next, Mozilla has confirmed that Namoroka will be a “minor update” and carry version number 3.6. Depending on your view, the update is not so minor, as Mozilla will upgrade Gecko to version 1.9.2, up from 1.9.1 in Firefox 3.5 and 1.9 in Firefox 3.0.  

Gecko 1.9.2 will deliver a few interface improvements, such as new graphical tab-switching behavior, which was originally scheduled to be included in Firefox 3.0, but made it only to the beta phase of 3.5 – and was removed from the browser with the second beta version. Gecko 1.9.2 will also be using one native widget per top-level content document.

Mozilla also claims that Firefox 3.6 will startup much faster than 3.5 and integrate enhancements to the TraceMonkey JavaScript engine. I have been using 3.6 alpha 1 for four days now and can honestly say that there is, subjectively, no noticeable difference in responsiveness or page load times between Firefox 3.5 and 3.6. But then I also have to admit that, most of the time, I can’t really tell a page load time difference between Chrome, Safari and Firefox, even if some JavaScript benchmarks claim that Chrome and Safari are about ten times faster than Firefox.   

I am confident to say that you won’t be able to tell much of a difference between Firefox 3.5 and 3.6 either. And needless to say, you should not be using version 3.6 at this time anyway, since it is an alpha release for developers. Feel free to test drive the browser yourself, but be aware that there are many bugs in this browser, about 3500, according to Mozilla’s current Bug List.

But, of course, I have taken this new alpha version through the most popular benchmarks and found that, with one exception, this early preview is quite apparently already much faster than version 3.5. In one case, the new browser outpaces the old by 28%.

Compared to the current version 3.5.2, the new Firefox 3.6 alpha 1 hit a score of 405 in Google’s V8 JavaScript benchmark, which is a 14% improvement over version 3.5 on my test system. The SunSpider score came in at 988.2 ms, 15% faster than Firefox 3.5. In Celtic Kane, a less known JavaScript benchmark, Firefox 3.6 was 9% slower than 3.5.

In flash performance, 3.6’s performance was slightly up over 3.5 (651 displayed animated objects vs. 636). The most significant performance increase was in Futuremark’s more comprehensive Peacekeeper benchmark, which showed a 28% jump from a score of 1964 to 2513 on this particular test system. Rounding out the test runs was the standard Acid3 web compatibility test, which showed a minor improvement from 93/100 to 94/100.
Overall, Firefox 3.6 alpha 1 has been a stable browser and I have not run into any crashes or major incompatibility concerns over the four day test period so far. In fact, it does not feel much different than Firefox 3.5, which means that the plan to release it as a minor update seems reasonable to me. The speed improvements definitely appear to be there, but they are not dramatic and certainly won’t blow your socks off.