Out of Memory Error Fiasco

[Shane Ross]

Trash your FCP prefs with FCP Rescue…see if that does anything for you.

Shane

Littlefrog Post
http://www.lfhd.net

[David Roth weiss]

Oops, forgot to mention, I did that first…

Keep thinking Shane. But I must warn you, this one really requires thinking outside the box, cuz I promise you, I did everything we would normally think of and then some…

DRW

[Dave Mac]

David,

A few things you may have already looked into…

Check to make sure _all_ of your assigned scratch disks have enough room. Check scratch disks for fragmentation (and defrag if necessary). Check your media, especially still images, to see if any files are corrupt (not so easy to check). Check rendering on a different project, with an entirely different set of media (to see if things are related to your current project and media, not with all use of FCP rendering).

A few things I have learned that may apply here…

During renders, underlying QuickTime (QT) framework(s) perform a lot of the “heavy lifting.” QT creates a lot of “UNIX temp files” and virtual memory, which reside on your startup volume. If QT runs into a “difficult” piece of media, those temp files can quickly grow to be several hundred GBs (and cause an error). As FCP users, It isn’t obvious to most to be aware of underlying system operations and _their_ scratch (UNIX temp) files. So, your startup volume may run “out of memory” because virtual memory files and/or temp/scratch files for system processes (namely QT) are filling up the volume (not easy to track, as they get automatically deleted, for the most part, after many error messages are displayed and FCP/QT is quit).

So, having insufficient free disk space on your startup volume, even if it isn’t assigned as a scratch disk in FCP, may still cause problems.

You may want to open the Console application and watch its log window as you run FCP and attempt to render. Also, it may be instructive to run Activity Monitor while running FCP to see all of the processes, their memory and disk usage, etc.

Let us know what you learn. Good luck.

-Dave

[David Roth weiss]

Dave,

Thanks for the ideas and encouragement. I think I have figured out the solution, or so it appears. Believe it or not, the idea for the fix came after a 1-min. discussion with a certified MAC guy who knows absolutely nothing at all about FCP.

The MAC guy told me that I needed to allocate more RAM to FCP. Of course I informed him that was not possible, as FCP automatically defaults to 100% allocation of the entire 2.5gb of RAM that it is capable of using. He said, then go to the window where that setting resides and change the setting to something else, then change it back to 100%. And he said, if there are other settings there, increase those allocations to something higher.

So, first I tweaked the RAM allocation down to 50% and then back to 100%. Then, I upped the Still Cache from 10% to 20%, and while I was at it I upped both Thumbnail Cache settings, doubling Disk to 11000 and doubling RAM to 1024. I have no idea what that did exactly, but it sure seems to have cured the problems I was having. Renders seem to be screaming along very nicely now and no out of memory errors whatsoever.

DRW

[Dave Mac]

David,

Glad to hear things seem to be working again. The system settings you tweaked likely have something to do with virtual memory usage and temp/cache files (nothing to do with FCP’s render or “scratch” files). Seems like quirky/buggy behavior with FCP. By changing the settings, some underlying system settings and temp/cache files likely get “refreshed/purged/recreated,” or some such thing…. 😉

It would be nice to know exactly what is happening, as this has been a recurring problem with FCP for quite a while. Would it be possible to try to get a clearer explanation from the Mac tech person?

I’ll try to remember this in case it happens to me (hopefully not).

It is curious to note that you had deleted the FCP preferences. Had you changed the default settings in the Memory & Cache pane before this happened? If not, it makes sense that the newly created preferences used the same/default settings (and didn’t fix things). I wonder if you had modified these settings from the defaults and then deleted the preferences when you encountered the problem that the newly created defaults would have fixed things “automatically” (since they were different from what they were last set to, in effect changing things under the hood as you did to fix things)???

-Dave