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Thunderbolt Improvements in the M1-Based Macs

Over at the OWC Rocket Yard blog, SoftRAID developer Tim Standing shares a welcome discovery about Apple’s new M1-based Macs. Although the new Macs have only two Thunderbolt ports, compared to four on the Intel-based 13-inch MacBook Pro and Mac mini, Standing discovered that each port has its own Thunderbolt bus. By comparison, each pair of Thunderbolt ports on the Intel-based Macs share a bus, meaning that they also share bandwidth. If you plug two fast drives into ports that share a bus, performance suffers. Standing also notes that the M1-based Macs have Thunderbolt 4, which differs from Apple’s implementation of Thunderbolt 3 in only one fundamental way: Thunderbolt 4 adds support for Thunderbolt hubs that let you add more ports.

So yes, the M1-based Macs may have only two Thunderbolt ports, but they’ll both provide full bandwidth and allow users to add more ports through a hub. And as you might suspect, OWC has a Thunderbolt Hub shipping soon for $149.OWC Thunderbolt Hub

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Comments About Thunderbolt Improvements in the M1-Based Macs

Notable Replies

  1. Great news. So, using OWC’s article (Intel Introduces Thunderbolt 4: What It Is and Does It Matter?) as reference, the only features preventing Apple from calling it Thunderbolt 4 are:

    • Support for two external displays. This is probably going to be the only difference users will notice or care about.
    • Intel VT-d based DMA protection. I’m assuming its not present because it probably makes no sense on a non-Intel processor. But maybe Apple has an ARM equivalent that would qualify.
  2. I doubt even that. Power users who absolutely need 3 monitors are unlikely to buy a low-end Mac, and in the event they do, they are by now probably aware they can hook up several more displays via inexpensive Display Link.

  3. I guess 2 TB4 ports should be enough for most people, but I would have liked to have 1 USB-A port on the MacBooks just so you can plug-in a USB stick without having to carry some dongle (potentially forgetting or loosing it at some point).

  4. Several years ago I bought a 128GB USB stick with USB-A on one side and USB-C on the other for maximum compatibility.

    USB-A is never going to appear on another Mac notebook. Might be time to move on from anger and denial to acceptance :wink:

  5. I have something similar, but my Windows friends (yes, I have those :wink: ) don’t.

    I’ve stopped being angry long ago, I’m just disappointed nowadays :wink:
    But never for long :slight_smile:

    Thanks, that is quite cool! Could use those for some of my older USB sticks. Could also solve the issue with USB sticks from my Windows friends, if I don’t forget to pack one in my bag.

  6. That’s key. I always have one or two of those in my bag. A colleague of mine actually has one on his keychain (in a tiny case).

  7. It’s in the Hall of Nostalgia, which includes Hypercard, Eudora, MacBook MagSafe. Yea, let’s put Firewire and the clickwheel in there as well.

  8. I plugged in an Apple Thunderbolt 3 to 2 adapter into my M1 MBAir. Not even recognized.

  9. Did you connect any device to the adapter? The adapter itself won’t show up as a device, but a TB2 device attached to it should appear in System Information as a normal Thunderbolt device.

  10. I tried 2 different devices - an OWC RAID array and a thunderbolt drive. Both work find on an older Mac Book Pro, but nothing on the M1 air.

  11. I used one to connect to my 2012 MacBook Air for migration and it worked fine.

  12. Speaking of keychains.


    There is of course cheaper stuff.

  13. Just wanted to post another confirmation that using the Apple Thunderbolt 3 to 2 adapter worked just fine with a Thunderbolt 2 cable to connect between my wife’s new MacBook Air and her 2013 model in Target Disk Mode. (I did a manual copy of her data, rather than using Migration Assistant, but it was problem-free.)

    For those reporting problems, if you’re still having them, it would be useful to provide complete details.

  14. Just wanted to post another confirmation that using the Apple Thunderbolt 3 to 2 adapter worked just fine with a Thunderbolt 2 cable to connect between my wife’s new MacBook Air and her 2013 model in Target Disk Mode. "

    Same here. The TB 3 to TB 2 adapter will work with a 2013 MBP even if it’s TB 1. It also works with a TB 4 dock but it won’t recognize the dock without a reboot.

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