Just bought a Mac mini with 256gb storage which is not enough. Portable SSD (e.g. Samsung T7) seems generate less heat during usage but slower speed. SSD with enclosure is fast but 40gbps enclosures are very pricy and produce a lot heat.
Also, do you think it's a good idea to put the OS into external drive as some apps require to be installed in internal drive and iCloud only work on internal drive.
You don't give us much info about your use case, why you need more storage, etc
As it so happens I did run my Mac Mini off an external Firewire drive, that was a few years back but not as far back as you might think. So yeah, you can run your Mac off an external drive but I wouldn't recommend it.
I don't know why apple would limit iCloud to internal drives only, but it sounds like the kind of anti-consumer narrowmindedness that made them the world dominating company they are today. Are you sure there is not some kind of work-around to this, like a symbolic link or something. Or did they specifically go out of their way to prevent this kind of thing? Given the number of Mac's, iPods, iPhones and iPads I've bought over the years, the fact they only give me a stingy 5GB of storage for all of them is why they arn't getting any more money out of me for their dumb cloud storage.
Do you even need space to sync everything with iCloud anyway? I thought this kind of thing was passe now. Also why I stopped using dropbox, it's next to impossible to actually get the darned thing to reliably actually download all the damn files and not screw everything up. Now that we have more, faster, cheaper storage than ever before they want to force me to not actually have stuff sync'd. At least that's how it 'works' on windows.
Also, I don't see why the apps need to be installed on the internal drive given OSX's (or whatever they call it this week) strong point was that you could literally drag the app bundle wherever and run it from anywhere. Or is that yet another way they just made things worse than they used to be?
I also presume the storage is soldered to the main board or something now. Back in the day you could pull a Mac Mini apart and upgrade the hard drive. I even had 2 hard drives in one once with a bracket that sat where the optical drive used to be.
Anyway, I guess I'm kinda ranty this morning, but unless you provide some reasons as to why you think you need to do what you think you want to do it's really hard to say what the solution is.
Welcome to the Apple ecosystem. Probably best to get a stand enclosure with nvme SSD support and extra IO. Please note that some enclosures appear to only support SATA m.2 SSDs.
https://www.amazon.com.au/Satechi-Stand-Enclosure-10Gbps-Stu…
What do you actually need the speed for? My missus has a WD HDD drive connected 24/7 to her 2012 imac for bulk storage.
I went through this 2 days ago and I just bought this.. ~A$126 delivered.
https://www.acasis.com/collections/acasis-ssd-enclosure/prod…
What model/year Mac mini?????