Hi, I recently got a Samsung T5 external SSD to use as a new boot drive for a late-2012 iMac. Formatted as APFS, used CCC to clone the internal drive to the SSD. Once booted, it is very fast. However, there is a 1-2 minute-long delay in between the startup chime and the system actually booting, that only occurs if the T5 is connected -- regardless of what drive is selected as the boot drive. I spoke with Samsung and they are aware of the issue. Carbon Copy Cloner also has a comment about it on their site. Samsung claims the issue exists with many SSDs, not just theirs. A CCC Support person said they've only heard about the T5 having this issue. I'm trying to decide how to resolve my issue. One work around is to format the drive as HFS+, but I'd rather not create an unsupported environment. So maybe an easier solution is to just buy a different drive. Can anyone confirm that their non-T5 SSD formatted as APFS either boots quickly without the startup lag, or that their non-T5 SSD does have the startup lag? Thanks! ----- Edit: I guess my question is this - Is anyone booting Mojave on an APFS-formatted SSD that is connected via USB, without a lengthy boot delay? If so, what SSD are you using?