Why does PrintJobMgr use 99% CPU?

i have an HP photosmart 8450 that my daughter queued up a bunch of print jobs to. it had no paper and so the jobs just sat there. the PrintJobMgr positively ate up my cpu so it is not a Canon problem.

Still having this issue with 100% usage while printing. Is there any way to mark this thread "unanswered" or should we start a new thread?

You need to start a new one! 🙂

Well the earlier post mentioning the Reset printing system option worked for me. However, it's now hidden in Leopard. In Tiger it was indeed in /Applications/Utilities/Printer Setup Utility. But in Leopard you need to open the Printer & Fax preference pane and then Control click on your printer to get a pop-up with "Reset printing system..." option.

I too have a Canon printer (IP4000) and had this problem show up after installing Bonjour for Windows under Parallels and tried unsuccessfully to print from a Windows app. Even after deleting the print job from the Canon utility and restarting the PrintJobMgr continued to use up 100% of one of my four CPU's in my Mac Pro.

When I "Reset printing system..." as above, it was fixed for me.

I have been dealing w/ runaway fan for a couple weeks - THANKS to Aaron - his fix was correct - opened System Prefs > Print/FAX > Print Queue and deleted the offending job - MY fan took about 90 sec to cycle all the way down, but it did - thanks again to all - now if I could only figure out why the AirPort doesn't work anymore...

Here's the confusion:

The Problem: While printing, the processor using 99-100% of the CPU. (This is a problem because it causes the fans to ramp up and the computer to get hot. When printing 100 pages, the machine becomes hot to the touch and sounds like it's a rocket ship.)

Proposed Solution 1: People are assuming that the processor is ALWAYS using 100% of the CPU. The solution proposed is to get rid of jammed print jobs by resetting the print system or deleting the print jobs. This solution works for the ALWAYS 100% problem, but that is NOT the problem here.

Proposed Solution 2: People think that the computer SHOULD use 100% of the CPU while printing, reasoning that the system is just making good use of its resources. This is FALSE. I can run Windows XP on the same machine, and print the same document faster with much LESS processor usage (typically about 5% or less). Clearly, the Mac system is using more resources than it should.

The REAL solution: This is the solution I want: Let me print a document to a Canon printer and use just the CPU cycles needed to print (which should be VERY small -- under 5%) while running Mac OS X.

YES! You guys are great, thanks for solving this for me. I found an accidentally-installed printer that had a bunch of active print jobs that my wife had forgotten about. They weren't showing in the dock so I had to access the Printer control panel to find them. Now they're deleted and all is well!