So I've got a M.2 Samsung EVO SSD with OSX installed and all my other files are on a 4tb WD Red HDD 5400rpm - music included.

Can't remember if this happens with video files as well but it's been happening quite often whilst listening music on iTunes: every other song gets interrupted like a glitch or skip or something. And it ain't corrupted files - if I play it again it will play just fine.

Anyone knows if this happens because the files are on a much slower drive? But then again shouldn't it have a buffer of some sort so this wouldn't happen…? I mean even old CD readers have a buffer so it won't skip so it should be common sense right…

EDIT to include a picture:

TL;DR: avoid APFS. It’s promising on paper but too buggy.

Further development might change that but as it is it ain't worth it.

I’ve had issues with APFS before but thought it was user error: couldn’t install an APFS drive on a new machine that haven’t been upgraded to Mojave and wouldn’t ‘see’ the drive - an iMac so imagine the hassle of opening it up again as I didn’t have a Mojave USB ready since I wasn’t expecting to have that issue.

To this day I can’t run Mojave on a RAID zero system - the option is there on the install but it won’t work.

A friend is having lots of issues servicing Mac Pros - every time it gets an update its drives fail. So much so that he started to tell his clients he won’t service any machine with a system later than Sierra.

But till this latest problem I still haven’t realised it could all be due to APFS - automatic and ‘mandatory’ with High Sierra and Mojave.

So what I did and recommend if anyone wants Mojave running on HFS file system:

-Install carbon copy cloner on either Mojave or High Sierra on the Mac you having issues due to APFS;

-Get a external SSD with HFS file system big enough to get the system cloned into it - and clone it.

-Reboot, press option, boot into the external drive. Run disk utility, wipe internal drive as HFS, run carbon copy clone again and this time do it the other way around: clone from external to internal drive.

There you have it: Mojave running on HFS. Or High Sierra if that's what you want.

Still on testing stages but all seems to be running ok and the issues reported on original post are gone!

Just don’t know what will happen if there are any other updates but with Catalina soon to be released I don’t think Apple will put any more effort in updating an OS that’s soon to be ‘obsolete’.

And when Catalina does get released I’ll do the same as above to get it running on HFS.

Until further development and considering my issues and my friend's issues I can’t un-recommend APFS enough!

EDIT: interesting my answer got demoted to ‘update'…

This solved the issue:

NVME M.2 SSD with adapter

Basically the adapter can touch the metal plate in the computer's slot so you need to cover the adapter with thermal tape like so:

Interestingly my answer got scored down by the person who suggested to replace the drive with the Apple proprietary one. That same person is always saying to replace instead of trying to find a solution to fix the problem which I wonder if this is the place for that.

I mean is this ‘Ifixit’ or ‘Iboughtnewtoreplaceit'…?