With an external CD drive connected to my CD-driverless 2016 model of MacBook Pro, I've noticed an issue when ripping CDs. And some experimentation has shown an odd issue – iTunes and newer MacBooks appear to have a problem.

So, to demonstrate what I mean, I did some tests. I have two MacBook Pros at home – a 2012 model, with built-in Superdrive, and a 2016 Touchbar model (no built-in drive).

I also have two external drives – a silver slot-in drive, bought about a year ago (to be honest, it's a cheap knock-off of Apple's Superdrive) and a white Liteon drive, which I've had for many years. Both of these drives use USB 2 connections and rip CDs at 24x speed (which is also the speed of the drive built into my 2012 MacBook Pro).

Lastly, I have two pieces of software for ripping CDs – iTunes and dBpoweramp CD Ripper. In both cases, I ripped at a constant 192 bkps, with error correction turned off. I only have iTunes on my 2002 MacBook Pro but, to be honest, I only use CD Ripper in this to demonstrate it's a software and not a hardware issue.

Oh, and let's not forget the CD I'm using – it's the soundtrack to Scott Pilgrim vs The World and runs at 57 minutes and 16 seconds. Before trying these tests the CD had only been played once (and that was to rip it to a hard drive when I first got it). The underside of the disc is clean and untarnished.

First of all, I used iTunes on my 2002 MacBook Pro…

Built-in Superdrive – 4 minutes, 1 second (14.3x)
Silver External USB Drive – 9 minutes, 17 seconds (6.2x)
White Liteon External USB Drive – 9 minutes, 54 seconds (5.8x)

Now, on the face of it, you may expect the external drives to be slower – it's plugged in via USB 2 after all, rather than the internal SATA connection, and they're both pretty consistent (you'd probably expect them to be closer as they're the same specifications but I guess variation will occur – they're close enough in this case).

Now, we try the same tests with iTunes on the 2016 MacBook Pro. We don't have a built-in drive here so the tests are using the external drives only…

Silver External USB Drive – 45 minutes, 40 seconds (1.3x)
White Liteon External USB Drive – 36 minutes, 1 second (1.6x)

As you can see, both are terrible times – not far off the same speed as just playing the audio. You'll also notice that the fastest has swapped – it's now the Liteon. 

During the ripping process both, but particularly the silver slot-in drive, make a lot of grinding noises and both cause iTunes to hang for some time when it starts – it's quite a while until it even begins to rip a single track. You can hear the disc whirring (and grinding) during this initial time but it was over 3.5 minutes before the slot-in drive even showed signs of ripping that first track.

Oh, and for the slot-in drive test, my MacBook then refused to eject the disc when the copying had finished, despite me having closed down iTunes – MacOS said the disc was already in use whenever I tried to eject it. This happens frequently on this MacBook only.

So, maybe the issue is the USB connection as both pieces of hardware are consistently bad? I'm connecting to the 2016 MacBook Pro using the Apple USB 3 to USB-C adapter in both cases but, yeah, it could be a hardware problem. Well, if I hadn't performed the above test but using the CD Ripper software instead…

Silver External USB Drive – 9 minutes, 17 seconds (6.2x)
White Liteon External USB Drive – 4 minutes, 1 second (14.3x)

Those are WAY better times, albeit that slot-in drive is over half as slow as the Liteon equivalent. But did you spot the Liteon time here is IDENTICAL to the one posted by the internal drive on the 2012 MacBook Pro? So these external drives are more than capable of keeping up with the internal Superdrive – the fact that they don't on the older MacBook is interesting but, of more concern, is what's going on with the newer model when iTunes is being used? The fact that iTunes locks up for nearly 4 minutes before even starting the copying process is concerning but then completing the process, at most, 1.6x speed is appalling.

I'd be interested to know if other uses of the Touchbar MacBook Pro see similar problems or if this could be a particular issue with mine. If you do get a chance to test, please let me know. For now, I'm sticking to using my old Liteon drive with CD ripper…