Week of Safari 4 – Day Three, Performance and Stability

Continuing my Week with Safari 4, I thought I’d tackle one of the major selling points of this release, as well as a question many of you will be asking seeing as this product is in Beta.


Apple have made a big deal about the performance improvements in Safari 4 with some outrageous claims of how fast Safari is compared to its competitors. Seeing as performance was one of my main reasons for considering switching browsers, this was a area of particular interest to me.

I want to point out at this stage that the following is simply my opinion and is based a completely unscientific day of usage. I’ve added some samples from OSX’s process viewer simply for comparison and illustrations sake. My test machine is a launch day MacBook which has a 2GHz Intel Core Duo CPU and 2Gb of RAM. It’s running the latest version of OSX, 10.5.6.

In the few days I’ve been using Safari 4 I would rate its speed as “blistering”. Loading pages seems quicker, and javascript-heavy pages, such as GMail and Google Reader and notably faster than FireFox, which has always struggled somewhat. Perhaps most impressive is that Safari uses nigh on zero CPU cycles when its idling, this is in sharp contrast to FireFox which always seems to be humming along using resources. The image below is a snapshot of the Safari 4 process after leaving it running for several hours.

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This second image is a snapshot of the FireFox process after a significantly shorter amount of time running.

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Both browsers had five tabs open with identical sites fully loaded. Each browser had been idling for around a minute. As you can see, Safari is using around half the CPU of FireFox. The additional memory usage of Safari can probably be attributed to the fact it had been running for a longer period than FireFox (therefore had more pages cached, and a longer history list).

However, the figures are largely meaningless seeing as in real world tests, Safari feels significantly faster, and over time seems to do a better job of releasing memory to other applications.


Considering Safari 4 is officially a Beta release, it’s very stable. So far, in three days, I’ve had one crash. This is comparable to my experience in FireFox over a similar amount of time with a similar usage pattern. I’m also pleased to report that I haven’t experienced any “hangs”, where the browser becomes unresponsive for a period of time. This was a particular problem for FireFox, which would often remain unresponsive for over 10 seconds, sometimes much longer, before regaining its composure and letting me back in. It’s annoying, frustrating and can really ruin a browsing session if you’re trying to achieve something.

I do need to point out at this stage that there are reports from Safari 4 users highlighting problems with certain plugins, or as they are termed in Safari world, Input Managers. I was sure to clear down my existing Safari installation before installing version 4, so I’ve avoided any of these problems. It might just be something that tips the balance with regards to Safari 4 for you if you rely on such adornments.

As I’ve said, these aren’t scientific tests, and as such should be taken at face value. As always, your mileage may vary.

Tomorrow I’ll be looking at why comparisons to FireFox will never be fair.