Xcode 10 runs really slow and slows my entire computer down I'm currently using Xcode 10.1 and it's driving me crazy, it slows my computer down to a point that it is unusable. Before I upgraded to Xcode 10 I was running the same project on Xcode 9 and High Sierra without any problems and with only half of the memory it currently has (8GB of Ram). I now have upgraded the memory to 16GB but it didn't make a difference.
FYI - I don't think the slow down has to do with Mojave 10.14.2 since I was experiencing the same issue with High Sierra and Xcode 10, which is the reason I upgraded to Mojave thinking that Xcode 10 would run smoother in the newest operating system.
Here are the specs of my computer:
Computer has a fusion drive.

Here is what I see in Activity Monitor for CPU and Memory usage:


Disk Activity

Any idea what could be wrong?
EDIT:
The Simulator may be the possible cause.
In the comments below I stated that the issue was resolved by uninstalling and reinstalling Xcode but I later found out that it wasn't true. The issue seems to be caused by the Simulator, what I noticed is that if I reboot my computer and don't use the Simulator, Xcode runs fine. But as soon as I use the Simulator, Xcode starts running slow even after closing the Simulator. I need to reboot and use Xcode without using the Simulator to temporarily fix the issue. I have been using hardware-devices for testing and Xcode seem to be running fine. Any thoughts?
Thanks
I do have the same issue - unlike many other posts on the Web, I only have one view controller with a couple of slides and views, so simplifying is not a solution for me - 

I suspect the simulator seems to slow things down - there is a SimStreamProcessorService which seems to take a lot of CPU time (look at Activity Monitor under %CPU) -

I restarted XCode and didn't use the simulator and it seems to be running fine.  I have a MacBookPro late 2011 with 16GB RAM running Sierra -