Xcode 7 performance issues Does anyone know how to improve xcodes memory performance. With iOS9 the mem usage jumps to ~4gb i have a macbook pro i5 2.3 8gb But this damn thing is eating everything! At times it takes 2-3 min to switch between swift files or move to another location in the same file.

If i switch to another program (Chrome, slack or skype) those run perfectly fine.
After some monitoring with Instruments i saw the following (Simulator running)


After running it for 20min or so the issue also occurs on Instruments
I have regular spikes of cpu usage of up to 106% (Not to sure how
that works)
I got the iOS 8.4 simulator to see if 9 was specifically causing the issue, issue still persists.
xcode virtual mem is 5gb
xcode real mem stays between 500-750mb and has the occasional jump to ~1gb
xcode compressed mem is ~350mb
xcode threads climbs to about 32/34 when the issue occurs


Exact issue description
At random intervals(cannot find exact replication steps) xcode will apear to "hang" i am unable to switch between files or scroll on any pane (code, file structure or overview).
Also if I switch to another application while this is happening and switch back xcode will not come into view.
This can occur when xcode or the simulator is not in view. 
There doesn't seem to be anything downloading in xcode or on the system.
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.