Yeah, this should absolutely be a priority 1 bug. Do they not have any macbook's to test this problem with?

My work rate has dropped at least 50% while using my Late 2013 macbook pro. This is the brand new model, the CPU should be fast enough to keep monodevelop going!

Why in the world am I getting 10+ second lag spikes when the game isn't even playing. It's ONLY Monodevelop c# coding and I'm constantly getting the little spinning colored circle for loading. This happens constantly even without building the project.

It can occur repeatedly every few seconds with each freeze up lasting between 5-20 seconds! It makes using Unity on a Macbook almost impossible! Really glad I'm almost ready with the first iOS build so I can switch back to PC until this gets sorted out!

I also get quite a bit more lag in editor mode compared to what I would expect with this PC's specs. For example simple things like GUI text may display when I start scenes in the Editor even when I have conditions setting their display to false in Start().

I feel like I'm beating a dead horse with so many repeated posts. But I didn't even notice that this was priority 2. At least it's severity 1 but it should be priority 1! I've never had an issue anywhere close to this disruptive to my work flow.

It really seems like this whole thing might be caused by the new MonoDevlop to me. I've been having problems with it even on PC with Unity freezing on Quit if MonoDevelop is open, this is 100% repro rate! So I have to close Unity first then close MonoDevelop or my Windows Unity freezes!

Yeah I second that the performance served by Unity on Mavericks is not acceptable. It is just impossible to use it - keeps freezing all the time, especially when in Play mode.
Unity team, do something about it immediately.

BTW, has anyone noticed this is listed as a P2 bug? I find this hard to believe. Unity, please convert this to a P1.

So FYI the Maverick BETA does not seem to make a difference in the long-term.

Same issues here, early 2011 mbp. Unity is very nearly unusable!

Just noticed that when these monodevelop freeze ups occur the Activity Monitor is reporting:

MonoDevelop-Unity % CPU = 236.3

How it possible for the CPU usage for 1 task to go over 100%? What in the heck is going on here very annoying...

Spoke too soon again! The "Put hard disks to sleep when possible" setting appeared to fix the problem for about 10-15 minutes but must have been a coincidence. This issue comes and goes... doesn't make sense.

Disabling that setting seemed to cause my Macbook to start using the fan a ton and it's usually silent... what a joke Apple come on this is unacceptable!

Or maybe it's Unity's fault who knows. But I'm just not going to comment this is fixed unless everything works fine for like a week straight, every time I think it's working it randomly stops working a day later...

OK well I spoke to soon the problem has come back. It seems most people are experiencing the problem in the Editor while the game is running? For me the problem only occurs in Monodevelop.

But after reading someone's comment here I saw the energy saver settings. The Late 2013 macbook pro with the Iris integrated graphics does not seem to have the "Automatic Graphics Switching" setting.

However, it does have a "Put hard disks to sleep when possible" setting. I just disabled this a few minutes ago but so far it seems to have fixed my Monodevelop problem. That would make sense I guess if the hard drive is asleep every time I try to build in MonoDevelop. It shouldn't put the hard drive to sleep when you are using a IDE but that's another story.

Would recommend you guys try this if you having Monodevelop problems! This issue has now gotten 9/10 of my votes.

Found what appears to be a fix.

Locate and install (at your own risk) Maverick Beta 10.9.1

I can confirm this OS update appears to have fixed the problem for me (at least i've been using Unity for about an hour with no more hangs! Will post back later today to confirm if fix still works)

if you are a dev I suppose you can maybe find the Mavericks beta direct from Apple via the dev center

[TEMPORARY FIX] We've found that if you're on a Mac laptop and turn off "Automatic Graphics Switching" in the Energy Saver control panel, the stuttering diminishes or goes away. Try it and post your results.