"3x Crash Host" in Compressor

[William Hohauser]

This error just started with me right after the Mac Pro audio update was installed. Some QuickTime files got this error when I use the QuickCluster the create MPEG2 file but not when I use "My Computer". Other QuickTime files don't have a problem at all.

Initially the only difference I could attribute between the error files and the others is that the problem files have NTSC renders of PAL DV files using the Natress filters. But that shouldn't be a problem if the final QuickTime files are self-contained. Of course the problem files are the longest ones. I have found discussions about the 3x crash problem on the Apple support site as well as other FCP discussion groups but no clear solution seemed to be posted except a suggestion to use Digital Rebellion's Preference Manager. While at the Digital Rebellion site I found "Compressor Repair" which I ran as it also can remove Compressor's preferences.

While they don't mention it in the Compressor Repair program I eventually found it necessary to restart since there were now two instances of My Computer and the Quick Cluster in the Compressor services pull-down menu. Before the restart, I ran a test 7:30 minute file which rendered a 2-pass "best" MPEG2 in 2:30 with all cores going and no crash! Feeling emboldened I tried one of the problem files. It started but only half the cores were running. Feeling like something was confused in the computer, I aborted the render and restarted the computer. Upon reboot I found that the service pull-down in Compressor had returned to normal. Also I checked the QMaster prefs and found that that "Compressor Repair" had reset the number of instances down to 1 so I returned it to 4 which had worked well before. That seemed to work fine until about 2/3 of the way in and I got the "3x crash HOST" error again.

After reseting Qmaster I tried 2 instances. That worked and at about the same speed as 4 instances did. An 80 minute file took 20 minutes to render a 2-pass "best" MPEG2 file. While watching the CPU usage in Activity Monitor I noticed that two instances in Qmaster reduced the entire CPU load by about a 1/4 versus four instances which would top out the CPUs which probably accounted for the crashes. I don't recall 4 instances topping out the CPUs before the Mac Pro audio update but I'm not entirely sure. The rendering time seems close to the same.

Anyway it's working again and I have posted this as a possible solution for anyone having problems with their QuickCluster.