iOS 11 Simulator unusable slow

I am experiencing this issue as well. I'm developing an app using MapKit and all was well using XCode 8 but after switching to Xcode 9 and using the Xcode 9 simulator (iOS 11), my app has slown down to a crawl. I am using the release build of Xcode 9 (9A235). The Apple Maps app also runs very poorly on the Xcode 9 simulator.

I am using a Macbook Pro 13'' (Early 2014) (MacbookPro11,1) with 16GB of RAM and a 3Ghz Intel Core i7. I am running macOS Sierra 10.12.6.

Installed Xcode v9.0 (9A235) yesterday via standard AppStore process and simulator is not usable with SpriteKit - sim runs at 1fps.

Same issue with final Xcode 9 release with map kit on Ios11. It is not usable.

Agreed...Xcode 9 simulator is unusable with my latest development project which was fine in the previous Xcode 8 simulator.

Agreed I do have a mac mini and I was using the iphone 7 plus emulator which may not be ideal but at least it worked before.

Come on Apple. you claim the editor is blazingly fast now, so why not make the simulator blazingly fast too.

Apple, please fix this. Xcode is now unusable for me and I have several projects with time limits. I'm running a two month old SSD very fast imac and it is freezing and hung up with the spinning wheel. Please fix.

I am not running mapkit. I am simple referring to just using xcode to edit my code. It hangs up and generally runs very slow. Please help.

Thank you.

Can anyone post a link as to how to go back to xcode 8? This is very bad. I cannot use xcode 9

Same issue. I have Mid-2012 MBP (non-retina), and my game runs like a slideshow on iOS 11 simulator. But there's two interesting things:

1) UI is still smooth, only graphics (OpenGL) is slow.

2) The same simulators but with iOS 8-10 runs very fast and smooth.

Maybe it's an old hardware problem? Is anyone here have this problem on newer devices (like 2015-2017 macs)?

UPD: digitoid said he has same issue on 2017 mac (https://forums.developer.apple.com/thread/83570#262452), so it is not hardware problem.

Same issue here. MacBook Pro 15" 2017. SceneKit. XCode 9 public release from App Store. iOS 11 simulator. Unusable, less than 1 FPS.

I have the latest (2017) iMac with 1TB SSD and 32GB RAM. Xcode 9 crawls. I can't drag a label on a storyboard without the pinwheel and the simulator is painfully slow. I guess I should downgrade to version 8, but not sure what issues that will cause. This is awful. Apple please fix and give us a little update on what's going on.

This is very frustrating. Apple is one of the richest companies in the world and Tim Cooke recently spoke about how important apps and the app store are to their strategy. He talked about sharing courseware so kids can learn to code. Yet, at the same time the development environment is broken/painfully crippled. Please fix this.

Thank you,

Yes, this is totally unacceptable from Apple. Who knows if their reading these comments, one can hope. But man, as others have stated so many times here. To put this update out there... it's just totally beyond the pale to do this to developers. I don't get it. The slowness, the map stuff, the spinning wheel. It's crazy.

mrsilverman, you mentioned a bit ago. How to go back to Xcode 8. I did that today. It's pretty trivial, thankfully. Just go to developer.apple.com and scroll down to more downloads under the Xcode blurb. It'll take you to a page where you can install 8.3.3. Just make sure in Finder to put your 9 maybe in a folder "Xcode 9" or something like that. Once 8.3.3 installs. You can put that in a separate folder. This seemed to work for me for having both installed. However, all that said, not much of a point having 9 open with where things stand.

Come on Apple. Please. Please. Fix this! Here's to hoping we see an update soon.

Thanks. I'm going to downgrade tonight. I cannot work in xcode 9. Apple, please fix.

EDIT: The problem below got fixed by First closing everything. Restarting.

Running the following:

rm -rf ~/Library/Caches/com.apple.dt.Xcode

sudo rm -rf ~/Library/Developer/Xcode/DerivedData

Then removing XCode, and re-installing xcode.

Original problem: XCode says Indexing... at the top, and it never finishes. The UI is frozen (Beach Balls of fun). Sometimes it unfreezes, and updates in batch, if you clicked a bunch of times. Then freezes again. I restarted my computer. Restarted xcode. Re-opened my project. Re-ran cocoapods. It does become responsive after opening. Then, when you click build, all **** breaks loose. Just in general tons slower than xcode 8 was.

When / If all indexing finished, clicking on one of the errors in the side panel froze xcode permanently. (Says not responding in activity monitor. have to close)

The build process actually freezes midway on step 242 out of 288 for instance, and sits there for 10 minutes, before i kill it. It actually worked last week, so not sure what changed since then.

Macbook Pro (2015) 16GB, i7 4700. SSD.

Yea, alex_frantic. It's totally unacceptable from Apple.

What your mentioning I too have experienced and at this point. It's been mentioned so many times on this thread. We can only hope that the persistent pounding away here will get their attention.

Whether its the slowness with the indexing, the map slowness, the CPU pegging when running the map in the simulator, the gesture slowness some people have mentioned, etc. It's terrible. I suppose if you have a "simple" project that doesn't use maps or maybe even need to use specif features of the 11 simulator. Then, yea, Xcode 9 can be your friend. Otherwise, if you wanna use it for what it was intended for... like iOS 11. Ummm... no.

In other words, Apple. Where are you? Are you listening to us? When will you reply to us?

Update: This bug is fixed in Xcode 9.1 beta 2.

There is a bug in OpenGLES.framework in the iOS 11/tvOS 11/watchOS 4 Simulators that causes them to skip loading the LLVM JIT and fall back to interpreting shaders. This has a severe performance impact on the Simulator since it is entirely software-rendered OpenGL (this includes CoreAnimation, SceneKit, etc).

As a temporary workaround you can copy libCoreVMClient.dylib from Beta 3 into the Xcode 9 GM and performance should be restored to what it was previously. This must be done for each platform runtime separately. Make sure you do a backup of the old file first, and be aware that each platform has its own unique binary so you cannot copy the same dylib into all three directories (nor can you use the one from macOS).

Did I mention making a backup first?

This is not an officially supported configuration and is only intended as a temporary workaround.

For iOS this is located at:

Xcode[-beta].app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks/OpenGLES.framework/libCoreVMClient.dylib

For tvOS this is located at:

Xcode[-beta].app/Contents/Developer/Platforms/AppleTVOS.platform/Developer/Library/CoreSimulator/Profiles/Runtimes/tvOS.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks/OpenGLES.framework/libCoreVMClient.dylib

For watchOS this is located at:

Xcode[-beta].app/Contents/Developer/Platforms/WatchOS.platform/Developer/Library/CoreSimulator/Profiles/Runtimes/watchOS.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks/OpenGLES.framework/libCoreVMClient.dylib

Russ, thanks for posting this workaround. Unfortunately i no longer have beta 3 around. Could you advise where to get it? Thanks again!