Xcode 6.1 and iOS Simulator 8.1 very slow to run

Question

I'm using Xcode 6.1 and iOS Simulator 8.1. It takes a long time to run the simple apps that I've written using the iOS Simulator. Build process was ok but then the iOS Simulator will show the black blank launch screen then the app screen for like 5 minutes before the app launch. Many times it shows error "Lost connection to iPhone 6(/5/4s)". Tried to re-start Xcode and iOS Simulator, and MacBook Pro multiple times already. Tried to reset "Content and Settings" in the iOS Stimulator, but doesn't help.

What could be the possible causes? Any advice/solution? Thank you.

Answer 1

I suggest that you boot up the device that you want to use prior to the Build&Run in Xcode. If you hit Build&Run in Xcode while the device is not booted, you will need to wait for the device to boot. This can take a long time depending on your I/O load (eg: if Spotlight is indexing at the same time you are trying to boot, or if your home directory is on a slow volume like a network mount).

Just open up iOS Simulator.app ahead of time and select the device you want to test on from the Hardware->Devices menu. Then it will be ready when you need it.