Speed up Mountain Lion

March 14th, 2013 by Mark Nanut Leave a reply »

MLUPDATE 15.3.2013: Today 10.8.3 update came out and it seems to work smoother than 10.8.2. Still, applying these tips will give you an even smoother performance.

So you have this feeling that Mountain Lion (10.8.2) on your new or old Mac feels sluggish. In this post I’ll give some extra tips on how to improve this. Keep in mind that these are merely ADDITIONAL tips that do work, and you shouldn’t ignore the more general optimizations (make sure you have enough RAM, upgrade SSD, have enough disk space left). Let me point out that Mountain Lion DOES invariably feel laggy also on relatively new and capable machines such as:

MacBook Pro quad i7 late 2011
(2.2GHz quad i7, 8 GB RAM, Radeon 6750M graphics and Intel HD 3000 graphics, 128 GB SATA3 SSD)

MacBook Air dual i5 mid 2011
(1.7GHz dual i5, 4 GB RAM, Intel HD 3000 graphics, 128 GB SATA3 SSD)

With these tips I substantially improved performance on both of them. These methods will also work and improve performance on older Core 2 Duo Macs as well, but I cannot tell whether the results will be as great. One thing to add: the explained methods work very well and Mountain Lion will work faster to the point of feeling very fast, yes, yet still not as fast as Snow Leopard 10.6.8 – at least on my quad MBP. That’s why I currently prefer using Snow Leopard 10.6.8 to Mountain Lion 10.8.2, which is something I wrote about in my earlier post.

1. First of all, disable vertical sync

I wrote before about disabling vsync (Beam Sync) via Quartz Debug app before and I keep successfully using this trick on Mountain Lion, with a few small changes. Note that disabling BeamSync works a bit differently (less optimal) on Mountain Lion (and Lion) versus, say, Snow Leopard and earlier. This is most obvious that if you merely disable BeamSync system-wide in Mountain Lion, the animations/transitions in Mission Control will become choppy/laggy (zooming in/out Mission Control, switching full screen apps), something which never happened with disabled BeamSync with Expose.app in Snow Leopard and earlier. We’ll fix these transitions later, however, the scrolling in Mountain Lion with disabled BeamSync works great and is super responsive with vsync off in most apps. So the idea is to keep vertical sync off and fix the transitions somehow.

symlinkGet Quartz Debug v4.2 from XCode or download it from OSX86.NET:

Run it, open “Quartz Debug settings”, enable “Force Quartz GL” and set Beam Sync to “Disable”.

That’s it. But keep the Quartz Debug app open (just hide it or minimize it) because the changes won’t stick if you quit the app (not even if you force-quit it, the way it used to work in the earlier versions of Quartz Debug). How to tell if your changes are active? Just drag any of the windows around and if you see some border tearing, then it works. :) Yes, screen tearing is an obvious side effect if you have vertical sync disabled, but that is a minor trade-off for speed.

Update 24.5.2013: Here’s a newer automator app that works with Quartz Debug 4.0 and Snow Leopard and later OSX versions. You can download QD 4.2 from here. Download the zip with automator app from here. Put the Quartz Debug app in the Application folder, then launch the automator app from anywhere. What the automator app does: it launches Quartz Debug, enables QuartzGL and disables BeamSync and hides Quartz Debug app. Changes won’t stick if we force-quit the app, so it must remain open – and hidden. That’s it, you can set the automator app to execute automatically at system launch.

So now you have vsync turned off and everything already feels faster. Let’s go on to the next step.

2. Show scroll bars only when scrolling – to fix scroll lag

In System Preferences > General, set scroll bars to show only “When scrolling”. This fixed choppy scrolling in a couple of apps and I decided to stick with this setting.

3. Disable laggy trackpad inertia scrolling

Inertia scrolling feels mostly laggy and Apple wants to force it down out throats. Disable it by going into System Preferences > Accessibility > Mouse & Trackpad > Trackpad options

and set “Scrolling: without inertia”

4. If you have two graphic chips, switch to a more powerful one (with GfxCardStatus)

Obviously, switching to a more powerful discrete graphic processor (say, Radeon 6750M/6770M, NVidia 330M/650M,…) will speed things up. But don’t worry, you can still have a fast Mountain Lion even if you only have integrated Intel HD 3000/HD 4000 graphics.

Contrary to the title, you don’t actually need GfxCardStatus program to switch to a more powerful graphic processor – you can do this in the Energy Saver preference pane as well by disabling “Automatic graphics switching”. It is just that it’s much more convenient to switch between discrete or integrated graphics with GfxCardStatus, so I definitely recommend installing it.

Download it from here: http://gfx.io/

5. Speeding up or disabling Mission Control transitions

So, we disabled BeamSync and now we have smooth scrolling, but somewhat choppy Mission Control transitions. Fortunately, in Mountain Lion there is actually an option to set transition duration. The shorter you set this, the less lag you will feel. You can not only shorten the transition time – you can also disable the animation completely.

To make a faster Mission Control animation, open up Terminal and type:

defaults write com.apple.dock expose-animation-duration -float 0.15

To disable animation completely, type:

defaults write com.apple.dock expose-animation-duration -float 0

Play with what works best for you.

6. Speeding up or disabling full-screen app switching animation

Unfortunately there is no system setting to kill or speed up the often unnecessary slow animation when switching between full screen apps, if you use apps in full-screen mode at all. Fortunately, a program exists, called TotalSpaces, which circumvents this limitation. With it you can dramatically speed up the transitions between desktops/fullscreen apps and even change the type of transition (Cube, Swap, Slide or Flip). You can also choose to not use transitions at all – switching between desktops will then happen instantly and save you a couple of milliseconds time at every switch, resulting in a lifetime saved over a course of a couple of million years. Worth a shot if you ask me. “I want more life, f***er!” :)

Note that TotalSpaces has no effect on zooming in/out of a full-screen mode. This zooming in/out might still feel slow and possibly even look ugly.

Get Totalspaces here: http://totalspaces.binaryage.com/

7. Have your browsing experience fully GPU-accelerated – use Chrome as your main browser

I admit it, I never really liked Chrome browser and have always treated it as some sort of google spyware. But with a lack of better options, I started looking into it and finally found it to be at least for now a FAR faster option than Safari or Firefox, especially with this setup of Mountain Lion I’m explaining in this post. Firefox feels choppy even if it has “hardware acceleration” enabled, while Safari is visibly faster than Firefox, but not without choppiness, and has on top of this the ultra annoying elastic scrolling, which I simply cannot stand. So I played around with advanced settings in Chrome and got it to work blazingly fast.

Type “chrome://flags” in the URL bar (omnibox) and tweak the settings:

GPU compositing on all pages: enabled
Threaded compositing: enabled
Disable GPU VSync: enabled (mind the wording – you are actually “enabling the disabling” of vsync in Chrome)

Then relaunch Chrome. You should have a super snappy Chrome browser now.

8. Switch to a 2D Dock

I usually do it via OnyX, but it can be also done via Terminal. To switch to 2D, type:

defaults write com.apple.dock no-glass -boolean YES

then restart Dock by typing killall Dock. To return to 3D dock, set the parameter to “NO” and restart the Dock.

9. Minimize with Scale effect

Go into System Preferences > Dock

and set “Minimize windows using” to “Scale effect”. For good measure, you can also disable “Animate opening applications”.

10. Disable elastic scrolling

defaults write -g NSScrollViewRubberbanding -int 0

11. Disable zooming in Accessibility preference pane

Go into System Preferences > Accessibility > Zoom

and uncheck all options.


All these tips should result in a dramatically more responsive and usable operating system. Of course there are many other things you can try if your system is slow, such as repairing permissions etc.

Hope all this works well for you. Cheers.

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