iMovie encoding differences between PPC/Intel

Discussion in 'Mac Apps and Mac App Store' started by dolphin842, Dec 1, 2006.

  1. dolphin842 macrumors 65816

    Jul 14, 2004
    Hi all,

    Perhaps this may or may not be already known in the greater Mac community, but I have a suspicion that Quicktime encoding in iMovie on intel is significantly slower than its PPC counterpart.

    I did some unscientific tests with my core duo iMac (1.8GHz, early 2006) and a dual 2.5GHz G5 in the school lab. I encoded a 4:13 DV movie with the following settings: 1000kbps, mpeg4 (standard, not h264), QVGA resolution. I clocked the time it took for each machine to encode and used Activity Monitor to observe the CPU percentage each machine was using along the way.

    PPC: With iMovie using 55-60% (I assume that's of one core, the figure that's in the process list?), or about 1.3 GHz, it took just over 2 minutes

    Intel: With iMovie using 80-100% of one core (1.44-1.8 GHz), the encode took 4 minutes and 40 seconds.

    I'd call shenanigans, but before I do, I'd like to see if other people have gotten similar discrepancies between PPC and Intel procs when exporting from iMovie. Anyone else have stories to tell?
  2. theBB macrumors 68020


    Jan 3, 2006
    How much RAM does each one have? Any other apps running in the background, especially for intel version? Anything that requires Rosetta such as MS Word?
  3. dolphin842 thread starter macrumors 65816

    Jul 14, 2004
    The G5 has 2 GB, the iMac has 1.5 GB... no taxing or Rosetta-requiring apps going on in the background for the iMac. When not encoding, both of the iMac's cores were around 98-99% idle.
  4. bankshot macrumors 65816


    Jan 23, 2003
    Southern California
    Interesting! I recall feeling a bit disappointed some time ago that a particular encode wasn't as fast as I thought it would be on my 2.0 original Macbook, as compared to my 733 MHz G4 tower. Then again, it took a few hours on the G4, so even getting down to an hour or hour and a half on the Macbook would still have "felt" slow.

    Maybe I'll do a more carefully measured test now and see what happens. I have to admit I'm kind of curious now.

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