Very slow tab switching in Xcode 4.5 (Mountain Lion)

Question

I recently upgraded my MacBook Pro (2.3 GHz Intel Core i5) from Lion to Mountain Lion and upgraded Xcode to the latest version 4.5 at the same time. I experienced one very annoying problem. During programming, I always had several openable bookmarks. Ever since I updated, every time I switch tabs, Xcode freezes a little (a couple of seconds). Anyone have a suggestion to solve this problem?

I followed the advice on removing project.xcworkspace for better performance. Which was soldered to help, but only for a short period of time.

Answer 1

This is a common problem and has been fixed in Xcode 4.5.1.

https://devforums.apple.com/thread/167765?tstart=0

Answer 2

If you have multiple partitions (the Lion backup may have been saved), make sure that xcode really comes from the Mountain Lion partition.

Updating the App Store App for Xcode is similar to the first Xcode.app that it finds and will apply any update for this version. In my case, it updated the (inactive) Lion section, even so I booted from the ML section. xcode-select did not complain when I tried to change it to the ML version.

So, I finished work with a great economy:

• do a chmod 000 /Volume/<old Lion partition>/Applications/Xcode.app
• installed a new copy on Xcode.app in /Applications
• check the purpose of the dock icon (you must specify ML Xcode.app)

My Xcode is still working now and it remains fast. You can get the Xcode dmg and command line tools from https://developer.apple.com/downloads/index.action . I don't think there is a difference in the binaries, but with DMG I could see where I lost Xcode.app.

Answer 3

I found your question before finding a partial solution.

To date, I find the Xcode 4.6.1 GUI dog slow for my taste, especially considering that I run on one year a Mac, SSD, compiled to 2 GB of RAM disk and still leave 6 GB of RAM. Even Eclipse is lightning fast compared to Xcode

4.5.1 has improved a little, but after using Xcode for a long time, I have no hope that some of its problems will ever be resolved.

Having said that, I noticed that the "Live Issues", the main toolbar and all the panels slow down the switching of tabs to the same extent. By far, the biggest intruders are the navigator panels.

Once I'm used to the minimalistic Xcode window, place some special task tabs, keep a separate window for xibs and recognize shortcuts to enable / disable panels, I no longer suffer so much from Xcode, but there is still something that can be clearly felt.

Answer 4

Make sure that ViewWillDisappear does not have heavy encoding. Also, if you have NSURLConnection or any other that has delegation methods, you should not call it when switching tabs.