Xcode 7 performance issues

I can't comment but I am running into the same issue with xcode and have a direction for you to try. Create a new profile on your mac and run xcode from there and check the memory usage for xcode, that should hopefully be down around normal levels. What that means i'm not sure yet, but it could help.

Update:

My problem was caused by too many provisioning profiles, this wasn't an issue I can recall from pre Xcode7, but maybe someone else can enlighten me. Any time any project was opened something happened that cause my xcode usage to spike up to 5.2GB uncompressed, but deleting about 1.5GB of provisioning profiles brought that usage back down to normal levels as described in this thread.

To find the files to delete go to:

${Your_Username}/Library/MobileDevice/Provisioning\ Profiles

Since you are developing - fire up Instruments and use it to profile Xcode.

You'll need to determine if storage/io is the cause of the slowdown or if it's CPU or if it's network.

From there, you can ask a follow on question once you have some data on the problem. My guess is Xcode could be downloading the new documentation - check for intalld/active network downloads. Or it could be symbolicating crash logs from all connected devices, or downloading symbol tables from connected devices, or running a sandbox, or ...

Basically, since Xcode is so large a tool, it's hard to know what subsystem you are even using without some data.

FWIW - here's a properly behaving, no simulator running, a dozen other apps running, Xcode done installing documentation Xcode using a hundred meg of RAM while open.

The Mac in question is up 3 days and has has a lot of mongodb and VirtualBox linux VM running which make the kernel larger than it would be at boot, but even that isn't causing any sort of memory pressure.

Was having the same problem - investigated and googled whole day yesterday and found out a solution. The problem seems to root from the TOOLTIPS that XCode tries to show for truncated filenames in the left pane of XCode.

So just widen the left pane and this problem no longer occurs for me. Please read my blog if you want details: http://xcodenoobies.blogspot.my/2016/05/how-to-fix-xcode-7-lag_17.html