Logic Studio apps MacBook Pro i7 - Mainstage 2 Problem: Random CPU Spikes


New Member
Hi there!

After happily using a Powerbook G4 for almost 6 years, Tascam us-122 and having Logic 7 (and later 8) installed , I finally bought the most powerful 15" MacBook Pro as the old G4 finally started to going on my nerves.

With the new laptop I upgraded to Logic9, but Mainstage was the reason I bought the new computer in the first place.

I had some experience using Mainstage1 live. It worked great for me, as I installed Sooperlooper and bought a FCB1010 plus Roland GI 20 for my bass guitar.

I was courious for the Mainstage Loopback and Playback functions, plus having some extra CPU Power.

After Installing Logic 9 and Mainstage 2 I did all the neccessary updates and started working.
Well, I invested 2.300 Euro for the Mac and Update.......and the whole thing is buggy as hell!!!!!!

I checked different Forums and it seems that Mainstage and 10.06.04 on laptops have a beef going on. There are random CPU spikes causing Midi Clock glitches and noises or vice versa. I dont know, but I guess its an internal clock problem.

Called the technical support of Apple. Supposed to be free for me, but in Germany u still pay 14 cent each minute and it takes ages to finally speak to the right person....at the end it did cost me about 5 Euros to be asked mostly pointless questions by 3 different people (so much for FREE).
I had to do it in english as the german support doesnt work on saturdays, wasnt easy...

I found out that they pretend to know nothing about the problem, even if its discussed hundred times in apples own forum (should have read those before, but I trusted 6 years of happy music moments with my g4).

if any one here knows a solution to that problem or can share experiences: please get in touch with me!

I wonder if Apple is going to do anything about this. Mainstage is supposed to be a professional tool for live performance. Apple obviously baits us with cheap software now to buy expensive hardware. Beware!

Q) what is your I/O buffer size? Try setting it to 128, or even 256 and see how things work then.

Q) Are you also running any 3d party plug-ins in your Mainstage "Concert" file? They might actually be the cause of the spiking.

What exactly do you mean "miid clock glitches"? The midi time code is not working properly? I do not understand what you are meaning.

What I suspect it might be is the way the software that prevents the hard drive from getting damaged when dropped is not exactly working properly.

George Leger III
hi I was also having a problem with mainstage-freezing on me, couldn't force quit the app.--had to shut down computer.I have a new imac i7,10.6.4 os,logic 9 and all the recent updates.Absolutely no problems with logic just every time I play with mainstage it freezes after about 10 minutes. I don't like shutting down my computer improperly so I'm afraid to try it again.
I realize it's probably my ignorance(being new to recording) but advice would be appreciated.Thanks
Well, answering the questions I was asking the other person would help... it's kind of like saying it's my car won't start, could it be the starter, gas, whatever. The questions help us to take an educated guess.

So, what more can you tell us?

things are working great suddenly,:confused:
I can set my in/out buffer down to 32 without problems now:)
I do have superior drummer 2 and when I was freezing I was on mainstage drums.
honestly,I don't know what was done different, seems like I was in a different area(template)? this last session. Maybe I was involving superior drummer 2 last time accidently.
I apparently was doing something drastically wrong before(pressing one wrong button):brkwl:
knock on wood everythings alright for now.
Thanks for your quick response.
I would like to make a suggestion to you regarding your I/O buffer settings: 32 is really freaking small, and placed a huge amount of overhead on a cpu, yes, even a very good cpu.

If you want to save yourself allot of issues when you start to really work (clicks and pops, overload issues, etc) you should consider increasing your buffer to 128 when recording, and higher when mixing. It can really make a difference in the end, and save you allot of headaches.

Try this: take a space designer and put it into the insert of a track, and select a long decaying IR. Use a small I/O and see how your cpu meters look. Then do the same thing, and increase the I/O to the next highest setting each time.

What you should see is the cpu meter going down each time you increase the buffer. The issue of a very large I/O is latency, the increase of the time it takes for the computer to sound after you send a VI a midi note.

128 is a good balance. The latency is between 3 and 6 milliseconds, way lower latency than a keyboard used to have, somewhere around 20 ms. In fact, it's lower than the latency you hear from an amp on a large stage while playing in a band...

In fact, I use a 128 buffer and have yet to have a vocalist or drummer comment on the delay (using a PCI based audio card anyways... Fire wire has an additional buffer that increases the time).

It's only a suggestion, but it is something I bring up with my clients when I build them a system or advise someone on using a new system.

Good luck...

George Leger III
hi georgelegeriii !!
sorry for the late reply on your comment to my problem. I ve been on holidays for a couple of weeks.
put my buffersize to 128 and 256. it works with 256 but not with 128. but the latency caused 256 samples is way to hard to handle for my live performance. according to what apple says, the problem is not caused by 3rd party plug ins.

with midi glitches, I ment that for example the mainstage loop device and the playback plug in get out of sync. sometimes after 15 minutes of playing, sometimes earlier. in some session more often, in some sessions sometimes only once.
its very random and all of the problems occure even with an empty rack and all 3rd party plugins deactivated.

I really apprechiate your help

greetings from germany