A Windows User and His New iMac – Day Seven

A Sunday with not much to do meant I could dig in and learn more about my iMac, but also fire up iMovie for my first video editing project on the new machine. It was a little…bumpy.

  • When I have three virtual desktops – email on the left, desktop in the middle, and Chrome on the right, and I’m in email and click on a link, it drops me into the Chrome virtual desktop (makes sense) but then it moves the Chrome virtual desktop over to the email virtual desktop (which makes no sense). I wonder if Apple does that to avoid the whiplash effect of going past your real desktop? I’d prefer to keep my virtual desktops in place though, because if I’m learning to lean on them when they move it defeats the purpose of the muscle memory of swipe left = email, swipe right = Chrome, etc. Is there a way to lock the virtual desktops in place?
  • I finally have a bit of quite time to fully edit a video in iMovie. Despite my earlier reported behaviour on import, the program is incredibly fluid and fast to edit the clips. I’ll be interested to see how it feels once I jam some 4K footage in there, and how good the 4K output quality is. Will Apple be thrifty on the bit-rate? can I even adjust it in iMovie? (yep, there’s a custom output)
  • I didn’t realize until now that the dock is hiding at the bottom in a virtual desktop – that’s slick.

  • I just accidentally discovered that the three-finder swipe up is how you access the virtual desktop controls. Wow, cool! I really should spend a few minutes learning all the gestures.
  • Clicking on an icon to open the app – whether newly launched or minimized is great – but clicking on it again doesn’t minimize it. That’s an odd omission.
  • I installed an app called iStat Menu and my jaw dropped when I saw it report I only had 33 GB storage left on my 512 GB SSD. What?? I looked at Trash and saw I had 64 GB worth of MKV files, along with another dozen GB of other deleted files. Oh, and over 50,000 photos and videos for another 110 GB. Holy crap. After emptying the trash – and getting a bunch of errors about locked files and files in use – I have 225 GB free again. I’m used to the Windows world where Microsoft sets a hefty but still limited Recycle Bin size, thus your storage will never be fully consumed by deleted items. Apple takes keeping deleted items very seriously, no matter the size. I suppose your average user wouldn’t accumulate 192 GB of trash files like I have after a matter of days, but I still find it odd there’s no automatic governance of trash size. Nothing in System Preferences that I can find. You can run a command line script to delete files over “x” days, or use an app called Hazel (which looks pretty slick actually). Do you really need a third party app to keep your Trash under control?

First iMovie Project

  • I already had some experience using iMovie on my Mac Mini, but it was obviously a much faster and smoother editing experience on the high-end iMac hardware vs. the five year old Mac Mini. I was zipping through the project quickly, and while it wasn’t a complex project at all (basically just clip trimming and merging), iMovie did exactly what I wanted. Until I rendered it…then some weirdness started to happen.

Screen Shot 2015-11-29 at 12.56.44 PM

  • I’m surprised that when using iMovie to render a project, it doesn’t use more of the CPU! The CPU use was about 400-500% for iMovie, and about 70% for ProTranscoderTool_sb – this is out of a total possible 800% (100% per CPU core x 4 cores, 100% per multi-thread x 4 added threads). I have it set to render “Better Quality”, Medium output, 1080p 60fps.
  • I’m fascinated by the fact that you can keep using iMovie, editing another project or even the one you just worked on, while the output is happening. That might be why Apple keeps the CPU use in check – to let people keep working. The system definitely shows some lag when rendering video, but it’s not terrible.


  • Oddly, after export (I saw the pop-up message saying the render was finished), I saw iMovie CPU usage spike to almost 600% (and ProTranscoderTool_sb to about 25%), and the fan spun up louder than any point during the render. What is it doing? I had cloned the first project while the first render was happening, but I hadn’t started the output yet. This has continued for several minutes now. The first render is complete because the temp file is gone from the desktop. When I go back into iMovie and start editing a project, CPU usage drops to 150% or so and the fan quiets down. When I move away from iMovie, CPU usage spikes to ~600% and the fan starts to go full tilt. I am so confused.
  • I noticed the icon for what looks like an iCloud upload in the upper-right corner of the project…does that mean it’s rendering a version specific to iCloud upload?

second render, low CPU use

  • I did a render of the edited down version of my first project, and upon render using exactly the same settings as the first one, I saw it jump to over 600% CPU usage (plus about 25% for the ProTranscoderTool_sb) for several minutes, with the fan spinning up to full tilt. After a few minutes of that, CPU usage dropped to below 100%, yet iMovie still says it’s rendering the video. What’s going on? It’s going to take forever to render the video using such a low level of CPU power…and now a few minutes later it’s at ~325% or so. Ridiculously inconsistent!
  • For the first several minutes of the second render, I couldn’t see the file on my desktop or the temporary file. It eventually appeared, along with the temp file. I am so confused.
  • I just saw a message saying my second edit was finished – the temp file is gone – yet iMovie still says “Creating movie”. CPU usage is still high, fan is still loud. What is it doing? I am so confused.
  • After several more minutes of high CPU usage and loud fan action, iMovie finished whatever it was doing. I have no extra video files on my desktop; iMovie has no additional Projects listed. I truly have no idea what it was doing.
  • I’ll be really curious to see what my next iMovie project is like, because this rendering process is kind of insane. Any iMovie expert out there want to explain to me what on earth it was doing? 🙂

Here’s how days eight and nine went.

New to this series? Start the journey with day one, or go back further to why I wanted to buy a Mac in the first place.