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Tech How-to: Fixing Pro Tools 10 CPU Overload Errors

A breakthrough! A breakthrough! I have been doing some experimenting with my recording rig, as described yesterday. Today it seems that greater success has come.

Running the newest version of Pro Tools – version 10 – hasn’t been without issue on my Macbook Pro. Although not recommended, I had been running an audio test from the primary (and only) internal drive. It was just easiest that way, but an error message continually popped up during playback: “A CPU overload error occurred. If this happens often, try increasing the H/W Buffer Size” in the Playback Engine Dialog, or removing some plug-ins. (-6101)”

With RAM maxed out at 8 GB and this machine not yet being a relic, it seemed something more was going on than the 5400 RPM drive simply not being able to keep up.

I changed Pro Tools settings multiple times, changed back and forth between 1 and 2 host processors, unplugged and plugged all the connections back in, and then something clicked. The newest part of this system I have been dealing with is the Aggregate I/O. For those unfamiliar, it used to be that Digidesign-branded hardware had to be connected to your computer to open the Pro Tools software, and that hardware also acted as the sound card… so speakers/headphones hooked up to it. Now an iLok is used, which is basically an oversized USB thumb drive that holds all your licenses and allows a user to open the software. This also allows you to use either the previously mentioned Digidesign hardware OR you can now use your computer’s internal sound card. Shabam!

What fixed this whole “CPU overload” debacle was taking away the aggregate setting and putting the focus solely on the externally-connected Mbox 2 (via “Setup” -> “Playback Engine” in the PT menu). It never occurred to me before that perhaps more-than-necessary processing was going on, due to sending signals to two sound cards.

Also, for good measure, I have hooked up an external, 7200 RPM hard drive to the Mbox 2, as the Macbook Pro only has one Firewire port, which is being used up by the Mbox 2 itself. I finally have a setup that isn’t clunking out every 15 seconds…. sooooo, if anyone else runs into a similar scenario, hopefully this gives you a solid starting point.


"Tech How-to: Fixing Pro Tools 10 CPU Overload Errors" (2011)

Written by: Justin Kilmer

Hey! Thanks for sticking with me until the end, and hopefully this troubleshooting info has helped. Help me out by commenting below and, if you really wanna say “thanks,” order one of my photo prints (even if only a postcard) here:


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