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Slow boot with SanDisk Extreme SSD on MacBook with Ventura

Hello, I have a MacBook Pro 14" 2023 with and M2 Pro and Ventura 13.5 and sometimes I start it using and external SanDisk Extreme SSD formatted with APFS (not encrypted) running Ventura 13.5, using the original cable that comes with the SSD (it's a USB-C to USB-C) and directly attached to a port on the Mac.

With this configuration, the boot takes more than 20 minutes and than fails, causing a reboot.

After many tries, I discovered that if I use the same cable, but with an adapter from USB-C to USB-A and then with another crappy adapter from USB-A to USB-C, the boot is blazing fast (it takes less than a minute).

However, if I run Blackmagic, the R/W speed is capped at about 40 MB/s (I suppose due to the USB speed "downgrade").

In the System Overview, it is listed as follows:



I tried to attached the SSD to all the USB ports, but the result is the same.

Just to add another info, I booted with this same SSD on a MacBook Pro with M1 using an hub and all was working fine, but without hub it didn't boot. Using the same hub on the M2 Pro, it don't boot.


Anyone has a solution or a suggestion for this issue?


Many thanks

MacBook Pro 14″

Posted on Aug 16, 2023 1:54 AM

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Posted on Aug 16, 2023 2:42 AM

My thought is the SSD's macOS was flawed in its creation or your cable setup is hindering the operation ... or both maybe.


My solution would be to erase the drive, recreated the bootable external SSD and attach with the appropriate cable to get max speed for the setup. Our T7 drives came with two cables each: USB-A and USB-C. The A type allow for read speed of about 540 MBps; the C type is right at the max advertise speed of the drive of 1050 MBps. Actual read speed for it is usually in the 900 MBps range.


Our Five Macs take maybe 30 seconds or so to fully boot from external. They all have Samsung T7 SSDs Attached directly to the Mac via the proper cable.


And they're all Intel Macs.

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9 replies
Question marked as Top-ranking reply

Aug 16, 2023 2:42 AM in response to Lted88

My thought is the SSD's macOS was flawed in its creation or your cable setup is hindering the operation ... or both maybe.


My solution would be to erase the drive, recreated the bootable external SSD and attach with the appropriate cable to get max speed for the setup. Our T7 drives came with two cables each: USB-A and USB-C. The A type allow for read speed of about 540 MBps; the C type is right at the max advertise speed of the drive of 1050 MBps. Actual read speed for it is usually in the 900 MBps range.


Our Five Macs take maybe 30 seconds or so to fully boot from external. They all have Samsung T7 SSDs Attached directly to the Mac via the proper cable.


And they're all Intel Macs.

Jan 22, 2024 5:23 PM in response to Lted88

did you ERASE that drive with Disk Utility when it was empty?


Readers have found that disks not erased are often still in Windows New Technology File System (NTFS) format, and utilities to read and write them are really S-L-O-W.


---------

The cables required for high speed data transfer over USB-C to Displays or to disk drives, MUST be certified and marked with the USB-C logo and SuperSpeed 10 G bits/sec or better, AND be shorter than ONE meter in length:



Cables "shipped in the box' are notorious for being 'lowest bidder' cables, and are not adequate unless marked as indicated above.


as HWTech suggested, ThunderBolt cables should be adequate, PROVIDED they are marked with the Thunderbolt logo AND ONE meter or shorter.

Aug 18, 2023 12:48 AM in response to Lted88

The 40MB/s transfer suggests the USB-C cable you are using is faulty and only running at USB2 speeds. Make sure you have the proper cable. The Apple USB-C charging cable is an example of a USB-C cable that is only capable of USB2 speeds. If the cable connector does not have a lightening bolt icon to symbolize Thunderbolt 3, then that cable may not be able to handle USB 3 speeds either. There are a lot of USB-C charging/syncing cables out there.


Also, check out the SanDisk support page to see if your SanDisk Extreme SSD needs a firmware update. The more recent version of the SSD had a known issue of losing data which the firmware update should resolve/prevent.

https://support-en.wd.com/app/firmwareupdate


Sep 4, 2023 10:00 AM in response to Lted88

Hello, here is a quick update about this topic. I solved with the suggestions from ku4hx (many thanks).

I connected the SSD using the original cable, erased it and formatted again as APFS, then I installed Ventura from scratch. After the installation and the reboot, I used Migration Assistant to recover my data using Time Machine.

I run Blackmagick and the shown speed was about 140 MB/s.

The strange thing is that, after another reboot, it didn't start and I had to reinstall again Ventura.

Since then I had no issue and everything works fine.

The boot time is now about 2 minutes (it was about 1 minute with the crappy adapter), but apart from this, everything is good again.

Jan 22, 2024 4:17 PM in response to Lted88

Hi just wanted to weigh in on this conversation on how my experience with a refurbished imac 2017 I bought ended up being so slow I thought there was malware or a virus in my computer. Firstly I downloaded clean my mac to see if there was any malware and after 2 hours scanning my machine there was nothing. I had recently bought a fast read write external ssd drive(picture here) as using Logic the program kept crashing halfway through a song and on the Logic Official website to avoid this use an external fast ssd drive. Save your project files and samples to that drive and I immediately saw a drastic improvement. Anyway soon after that my machine just started to get so slow to do normal things like even opening programs I decided to copy my entire drive or clone it backup or whatever you want to call it using disk manager. You can do it either way also using carbon clone copier ccc but I opted for using disk manager. Keep in mind my disc read write speed with the internal drive was around 50 mbs which was extremely slow even start up took over 10 minutes! After all was done and now booting of this external hard drive I checked my disk speed and it packed a whopping 900 megabytes per second!! Even startup was less than a minute. It was pretty much like a new computer but a more expensive Mac and considering I only bought the ssd for $130 Australian it was an amazing transformation. Make sure your ssd has fast read and write speeds don't go cheap which for external drives they are very cheap these days anyway. Hope this helps for anyone who wants a faster Mac.

Slow boot with SanDisk Extreme SSD on MacBook with Ventura

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