Mac Pro + Handbrake encoding slowdowns

Discussion in 'Mac Pro' started by Draeconis, Oct 18, 2010.

  1. Draeconis macrumors 6502a

    May 6, 2008
    I ran into a bit of weirdness last night when converting a bunch of Xvid encoded AVI's over to H.264 m4v's using Handbrake.

    The reason I'm posting here is I think there might be an issue with the hard disk. To begin with, it ran (using 2-pass, turbo first pass) fine, up to finishing the turbo first pass, then it'd hang for about a minute, then carry on with the 2nd pass, running at around 300-400fps (not bad eh!).

    At around 40-50%, the hard disk starts sounding like it's performing a lot of tasks, even if nothing else is running. fps drops to around 100, then dips down to 30 or so and stays there. Entire system becomes slow / unresponsive.

    Seeing as the source files and destination for the output were on the same 2Tb drive (25% full), I wondered if perhaps this was too much for one drive to cope with (I'd previously been ripping videos / DVDs to an External drive, and never had this issue). I wiped an external drive, loaded the AVI's, and used it as a source drive, so all my main OS drive had to do was write the file, rather than both read and write at the same time.

    Same issue, but only for the first file. After this, the whole process ran smoothly.

    I'm not sure if the issue might have been that I was also copying different files as well as using handbrake, but despite stopping all other activities, this problem persisted, despite reboots, for a while.

    I'm a bit baffled, anyone have any ideas?
  2. Infrared macrumors 68000


    Mar 28, 2007
    Did you check memory usage? Those symptoms sound exactly like what
    can happen when free memory is running low.
  3. Draeconis thread starter macrumors 6502a

    May 6, 2008
    My Mac Pro has at least 4Gb free if not more when ripping.
  4. SpookyLars macrumors 6502

    Jul 21, 2008
    I had a similar situation with Handbrake (stalled encoding and strange disk activity). The problem was caused by the file that I wanted to convert. Try another app.
  5. Draeconis thread starter macrumors 6502a

    May 6, 2008
    I've used Evom, but the output files were twice the size and the quality was poor. I'm not sure it even gives you the option to alter the video converting properties since I believe it's designed just to be simple.

    When Handbrake decides not to have a fit, I can get the filesize to stay roughly the same with almost no loss of quality, which is exactly what I want. I wonder when 0.9.5 is coming out? :p

    Still, it's nice to hear that it's unlikely to be my hard drive!
  6. dissolve macrumors 6502a

    Aug 23, 2009
    You could try a nightly or run in through HandbrakeCLI. I've had a lot of luck using command line with my conversion routine. I haven't read about your specific issue, but I've seen cases where the GUI app impacts performance. Could be worth a try.
  7. Draeconis thread starter macrumors 6502a

    May 6, 2008
    Thanks, I'm sure all the CLI commands are in the documentation, I'll give that a go!

Share This Page