iMAC not handling HD editing well.

Discussion in 'iMac' started by erosenfeld, Dec 23, 2010.

  1. erosenfeld macrumors newbie

    Dec 23, 2010
    I've been editing SD forever and only now beginning to edit HD with new job. They bought me an iMAC and editing with Final Cut. Rendering is super slow, play back is clunky... just not happy with the work flow. Although I've been editing tv spots for 20 years, HD is new to me and I'm needing some advice. Should they have purchased me a MACPro... or should an iMAC be able to handle the HD clips? Thanks! Eric
  2. wrldwzrd89 macrumors G5


    Jun 6, 2003
    Solon, OH
    First of all... the obvious questions. Which iMac do you have? (If it helps any, this page makes identifying which iMac you're using easier.) Which version of Mac OS X are you running? (Apple menu -> About This Mac is the place to go for that.) How much RAM does your iMac have in it? (Apple menu -> About This Mac -> Click button at bottom) How big is your HDD/SSD?
  3. erosenfeld thread starter macrumors newbie

    Dec 23, 2010
    Computer specs

    I've got a Mac OS X v. 10.6.5; 2.93 GHz Intel Core i7; 16GB 1333 MHz DDR3 Memory. Does this help? Thanks for responding.
  4. wrldwzrd89 macrumors G5


    Jun 6, 2003
    Solon, OH
    Your iMac is definitely beefy enough for HD editing. Though I know even less than you about HD editing, what I do know is this:
    • Keeping your project entirely in RAM is very difficult, no matter what computer you have.
    • Having a good scratch disk is important too. I usually recommend external drives for this purpose, but the biggest problem with those is that their spinning platter holds them back compared to SSDs.
    • On the other hand, an SSD scratch disk will be super-fast, but an external is NOT recommended due to the interface not being able to keep up with the drive.
    • If you have a fast external, set it to be your scratch disk - but do NOT use your Time Machine disk, if you have one.
  5. aki macrumors 6502a

    Mar 2, 2004
    Your machine should have no issues editing HD. Something must be up.

    It's very difficult to guess but one obvious thing - you aren't trying to edit in AVCHD or anything are you? You let it transcode to prores or whatever?

    Anyway, it's not a hardware issue. I edit HD on a 3.06 iMac regularly.

    Hope you figure it out!

    Edit: Oh as regards rendering - that can take some time, on any machine. I'm not sure if you are talking Motion renders (they can take a loooot of time once they get complex) or just regular timeline on the fly-type renders. The latter should not be especially slow.
  6. HobeSoundDarryl, Dec 23, 2010
    Last edited: Dec 23, 2010

    HobeSoundDarryl macrumors 604


    Feb 8, 2004
    Hobe Sound, FL (20 miles north of Palm Beach)
    You've got near max horsepower with that i7. You have max RAM in that iMac. The graphics card in that Mac is plenty capable for HD editing. I edit a fair amount of HD video on the same iMac with only 12GB of that RAM... no issues.

    Please describe more details to help us narrow in on your issue. Specifically:
    • What kind of HD are you editing (resolution)?
    • What is the source of the HD (what kind of camera)?
    • Are you giving the raw HD video time to be read into the Final Cut (video ProRes) format before you start editing?
    • What version of Final Cut are you using?
    • Consider trying to import and edit a few minutes of the same problematic HD video in the consumer product (iMovie). Did it also struggle with the video? Did a default render of the video from iMovie also stutter?
    • What kind of edits are you trying to do that are yielding the negative experience? Stock (included apple) edit functions or third party add-ons? If the latter, which ones are you using?
    • Is your iMac functioning well otherwise? For example, have you tried any of your SD videos to see if they also suffer the stuttering, etc? Youtube? Test playback of some of the Quicktime movie trailers at various resolutions from the Apple website and see how they fare on this iMac. If you have any previously rendered HD video try playing it back on that iMac and see if it plays smoothly
    • Did the 16GB of RAM come from Apple, or is some of it third party RAM?
    • What kind of working (scratch) disc are you using? Is it just a single drive or RAID setup?
    • How is the scratch disc attached to your iMac? Local (maybe via firewire or USB2 cable)? Network? If the latter, wired or wireless?
    • Are you attempting to edit & render at the same time? Are you running memory or CPU-intense programs at the same time you're trying to edit this HD?
    • When you render are you using a default "save as" option or are you customizing the output? If the latter what kinds of settings are you changing?
    • For one of your stuttering renders, open it in Quicktime. In the Window menu, choose Show Movie Inspector. What do you see next to: Format, FPS, Playing FPS, Data Size, Data Rate, Normal Size and Current Size?
    • Do you play any graphics & animation-intense games? If so, fire up one and max out the display and animation settings. Did it play back pretty smoothly on that iMac (modern, intense games are likely to tax the CPU & graphics card more than just about any HD video editing you might be doing). If the game plays smoothly, you can rule out a lot of potential hardware issues.

    Answers to these kinds of questions will likely zoom right into the problem. Unless that iMac is behaving poorly in everything, the hardware should be plenty capable. If the iMac is performing poorly in ALL tasks, you might have a hardware problem, but that's a simple fix/swap at an Apple store (if that's the case).

Share This Page