Out of CPU Resources

[erant1]

I am running a PT HD4 Accel (7.3.1) system on a Mac DP G4. Lots of power, and I never use up all of the available chips. Today I was attempting to bounce a mix to disk, and about 20 seconds prior to completion received a message that my CPU resources were too low, and that I should remove some RTAS plug-ins and try again. I did some internal mixes of tracks with RTAS plugs to new tracks and then deactivated the tracks with the RTAS plugs. I also looked at the CPU usage meter during playback, which showed almost no CPU use. I also have the hardware set to the highest level of CPU usage - 90%.

I ran the bounce to disk again, and received the same message, so I removed all of the remaining RTAS plugs - only two. Same message again, with no RTAS plugs running.

I'd appreciate any ideas on what may be causing this error message - is there potentially some other service that's consuming CPU resources? I have no other programs running concurrent with PT, and during playback the CPU meter continues to show very low usage.

Thanks!