On Safari 5.1 performance issues


Lately I have noticed an interesting trend, both on Twitter and on some blogs I read on a regular basis: people complaining about Safari 5.1 performance. Many seem to agree that it has noticeably worsened compared with Safari 5.0.x. Some also add that Google Chrome, in their experience, is noticeably faster than Safari.

Tim Bray:

For some years, Safari has been my default browser. I generally prefer its choices in framing and ergonomics and shortcuts over all others. But I’ve had to stop using it.

Via John Gruber, who added:

I’m seeing the same things Bray is with Safari for Mac, particularly the performance problems when you have a lot of windows and tabs open.

Via Marco Arment, who added:

I’m also frustrated by the same performance problems with Safari 5.1 on Lion, although it was similar on Snow Leopard as of my (relatively late) Lion upgrade two weeks ago.

I don’t even have Flash installed, so I can’t blame that: Safari 5.1 is just incredibly slow in general web rendering, scrolling, and other interactions. It’s a huge regression from the performance of Safari 5.0, and feels even slower than Mobile Safari on my iPad 2 at times.

I have to say that — while I too have noticed a general worsening of Safari 5.1’s performance compared with Safari 5.0.x (or even with Safari 4.x on Mac OS X Tiger, for that matter) — I can’t say that my user experience with Safari has become ‘frustrating’. It still feels responsive as regards to scrolling and other interactions. Furthermore, on my system I haven’t noticed this evident performance gap between Chrome and Safari other people are claiming.

Of course there are some variables at play, and I guess these differences depend on system configuration and browser usage. Since upgrading to Safari 5.1, the only mildly annoying thing I have noticed is the infamous ‘page reloading’ issue where sometimes, when jumping to another tab, the previously loaded webpage doesn’t appear to be cached and is force-reloaded. For this matter I lost a long comment I was posting on a blog: I opened another tab to check an article and a link to corroborate what I was writing, returned to the comment page and Safari told me that it wasn’t responding and that it had to force-reload it.

So yes, annoying, but apart from this I haven’t felt Safari to be remarkably slower than the previous version or than Google Chrome. And I usually have at least 8–9 tabs open. For the sake of comparison, here’s some more information about my system: my main Mac is a 15-inch MacBook Pro (mid-2009, 2.66 GHz Core 2 Duo). I’m still using Snow Leopard (10.6.8, fully updated). I have disabled Flash entirely, except from the built-in plugin in Google Chrome. Also worth noting is that I use Safari without extensions. Another thing worth mentioning is that Safari feels somewhat more stable after disabling the caches (Develop > Disable Caches), which actually sounds paradoxical if you consider the force-reload issue mentioned above. It’s just a feeling though, one of the things you try while troubleshooting. I’m not saying that disabling caches is an effectual remedy. It may depend on something entirely different.

It would be interesting to know about your experience with Safari 5.1 (if it’s your main browser). Give some feedback if you like, and let’s see how your mileage varies.

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  1. To me, the greatest problem of Safari is its huge memory consuption. It’s usually around 6–700 MB, but sometimes I’ve even seen it at 1,5 GB.
    It happens to see the window going blank for a second or two, but it doesn’t appear to be a reload (i.e. an unsent comment on Facebook still appear in its textarea).
    I’m hoping that the new multiprocess architecture will be extended to each tab or window so memory footprint will go down as soon as you close a tab.

  2. Safari is VERY slow when I keep open a lot of tabs (for a lot I mean 15 or more) and eats lot of RAM.
    Sometimes it blocks even with only 2 tabs open, there is disk activity and no network traffic, then after some seconds it stops reading and starts loading the page.
    And of course the reloading page bug is very annoying when working online, especially with lot of tabs open.
    Safari is a little slower than Chrome or Firefox but nothing dramatic: the problem is that the browser is sluggish, busy doing things I don’t understand. Apple should fix the program as soon as possible.

  3. Lobato says

    Safari 5.1 has turned simply unusable to me. I keep many tabs/windows open (about 20–30 sites at the same time), leave it there, and specially when I open a new tab or window, it will beachball all windows for as long as 1 or 2 minutes. Really. It’s not that it froze, disk activity goes crazy reading something and it will eventually unlock, but by the time it comes back, I’ve already opened Chrome and did what I needed.

    And this happens every few hours. So yeah, I’m definitely ditching Safari until they get this fixed on a next update.

  4. Paul says

    +1000 to all the posts. The extremely sluggish Safari 5.1 performance turned into an impression of “slow mac” (MBP17” 2.93 Core2Duo, 8 GB RAM, SSD Vertex 128GB)…
    WIll leave Safari out of the game until it gets an update. A lot of annoying bugs + terrible performance (websites loading, scrolling, even typing text in gmail is like running Win7 on an old Pentium 166MMX =) ).

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