External SSD: No UASP - 10.13.6

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Level 1

8 points

External SSD: No UASP - 10.13.6

Hey folks,

I have a serious problem on my macbook pro retina 15" late 13: With no external USB 3.0 drive, may it be a bulk case with an ssd, a ready to use external drive from seagate or a m.2 USB 3.1 Case, I get UASP to work correctly.

I did the check via iroeg, via software extensions and via speed tests and my drives, especially my new m.2 SSD, definitely don't work in UASP mode, but all of the drives support it and I even bought a new case with user reviews pointing out that this case works with UASP under macOS.

I'm now a little bit desperate and dont know what to do haha. I even updated the firmware on the USB case, but that didnt help at all. Is there something I am missing?

MacBook Pro with Retina display, macOS High Sierra (10.13.6)

Posted on Nov 2, 2018 6:09 AM

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Answer 1

BDAqua

Level 10

250,319 points

Nov 2, 2018 6:54 AM in response to jevesstobs

Apple added native support for UAS to OS X 10.8 Mountain Lion; drives using UAS show up in (Apple menu -> About This Mac) -> System Information -> Software -> Extensions as IOUSBAttachedSCSI (or IOUSBMassStorageUASDriver, depending on the version of OS X) "Loaded: Yes".^[16] Drives listed with "Loaded: No" are defaulting the older, slower Bulk Only Transport (BOT) mode. This may occur if the drive's USB controller, the Mac's USB port, or any attached USB hub doesn't support UASP mode.

https://en.wikipedia.org/wiki/USB_Attached_SCSI

So, what does (Apple menu -> About This Mac) -> System Information -> Software -> Extensions as IOUSBAttachedSCSI (or IOUSBMassStorageUASDriver, depending on the version of OS X) "Loaded: Yes" say?

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Answer 2

jevesstobs Author

Level 1

8 points

Nov 3, 2018 5:58 AM in response to BDAqua

I kind of solved it: If I set the drive to APFS, UASP works. Before it was exFAT. So okay, Apple just supports their own stuff....but the big question is, why does UASP not work with my HFS Time Machine drive?

Question to the Apple Team: why do you not support UASP on other filesystems than APFS?

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