It's just not Mainstage, I am finding that Alchemy will kill my mix in Logic X. I am running Logic 10.2.2 and I am finding that it will be OK for a little bit, but when I try to do some basic sound designs in Alchemy, i.e. use a couple modulations and maybe play with some of the internal effects in - it will jack up the processor to an ungodly amount of 135% percent.
Also, I found the memory will start to climb or leak really bad! My only course of action is to close my project and quit Logic, and just open it up again and just don't use Alchemy. I am almost tempted to just scrap Logic and use Ableton Live on my Windows 7 Laptop. My goal is to focus on sound design and mixing, but I am finding that I have to spend to much time troubleshooting Logic X issues... I'm a long time Logic user and I have never seen it as bad as it is now...
Maybe this is due to the version of Logic X I am running and maybe I need to go back a version, like 10.1? I can't use the newer 10.4 version, that will force me to upgrade Mavericks to El Capitan and I can't do that. Because, I'd have to buy a new machine, and I can't afford the price of a new Mac right now... My goal here is to just make music.. not spend my time upgrading software and hardware, ugh!!
I half wonder if this is due to some sloppy code with the integration of Alchemy in Logic X?? I know for sure, It's not like my mac is under powered, I am running Mavericks 10.9.5 on an older Mac Pro with a custom 2 x 3 Ghz Quad-Core processor rig with 32GB of memory and I don't use 3rd party plugs. And as soon as I open Logic X and start to use Alchemy, my memory use will slowly start to climb to an ungodly amount, 29 GB!!!
Anyhow, you can really see my frustration with Apple in general, It seems, I had better mixes with Logic 9 on old iMac with Snow Leopard.