External SSD as swap RAM substitute?

[janat]

People say external SSD loses a lot of speed. I can’t find anything that proves that. Research suggests there’re SSD that work at 1/2 speed of ddr4 RAM. I can’t configure Mac mini I’d like to buy therefore I want the SSD as great swap disk.

 

[smirking]

What's the exact machine are you considering this for?

Why are you considering this? Are you afraid of exhausting the SSD on your Mac by swapping?

If so read this thread starting at this point:

ssd swap - high usage of Terabytes Written

Very sceptical about this. I don't think anyone in this monster thread has reported a dead Mac from high SSD life, even the 1.15 petabyte poster. Can you send a link? I also have no idea why launchd or the others write so much, which seems to be unaffected whether I am using the machine or...

forums.macrumors.com

 

[janat]

What's the exact machine are you considering this for?

Why are you considering this? Are you afraid of exhausting the SSD on your Mac by swapping?

If so read this thread starting at this point:

ssd swap - high usage of Terabytes Written

Very sceptical about this. I don't think anyone in this monster thread has reported a dead Mac from high SSD life, even the 1.15 petabyte poster. Can you send a link? I also have no idea why launchd or the others write so much, which seems to be unaffected whether I am using the machine or...

forums.macrumors.com

I edited the first post. The idea is not upgrade RAM, but try to have decent swap speeds with external storage.

 

[smirking]

The speed will likely be acceptable, but the latency will be more noticeable. Again, are you doing this because you're worried about causing wear and tear on your SSD? If so, please read that thread I mentioned above. Apple's SSDs are very robust.

I'm a developer and a photographer. I've pushed the original 8GB M1 MBP way past any reasonable expectations and it performed very well. It performed well because the way the swap was handled was excellent.

Even though I was under severe memory pressure almost constantly, there was hardly any real world impact. I don't think you would be able to say the same if you had the swap go to an external drive.

 

[salamanderjuice]

External drives do lose a lot of speed. You can get 7000+ MB/s SSDs like the Samsung 990 Pro. The M2 Mac Mini has 40Gbp/s (note this is GigaBIT not GigaBYTE) Thunderbolt 4 ports, so at best you'd be getting 5000 MB/s with an enclosure that can take full advantage of TB4. Typically with with a random USB 3 drive you're more likely getting 5Gb/s or 10Gbp/s which is 625MB/s to 1250MB/s. Even slow 2133MHz DDR4 is 17000MB/s.

I think the only way it will be acceptable is if you're using lots of small programs that fit within your RAM and swapping between them. Anything that requires more RAM than the computer has will be a miserable slow mess.

Consider getting a Mac Studio or a PC if you need more RAM than the Mini offers. You can get a similarly sized Mini PC from companies like Beelink or Minisforum with 32GB of RAM for pretty similar pricing to what Apple asks for a base model mini. They can often be upgraded to 64GB if you need more too.

 

[Fishrrman]

You don't want to even try this.
You just... don't.

DON'T BUY a Mini UNLESS it has "enough RAM" for what you intend to use it for.

The ABSOLUTE MINIMUM you should get is 16gb.
NOTHING LESS.

If the Mini doesn't have it, then don't buy it.

 

[janat]

External drives do lose a lot of speed. You can get 7000+ MB/s SSDs like the Samsung 990 Pro. The M2 Mac Mini has 40Gbp/s (note this is GigaBIT not GigaBYTE) Thunderbolt 4 ports, so at best you'd be getting 5000 MB/s with an enclosure that can take full advantage of TB4. Typically with with a random USB 3 drive you're more likely getting 5Gb/s or 10Gbp/s which is 625MB/s to 1250MB/s. Even slow 2133MHz DDR4 is 17000MB/s.

I think the only way it will be acceptable is if you're using lots of small programs that fit within your RAM and swapping between them. Anything that requires more RAM than the computer has will be a miserable slow mess.

Consider getting a Mac Studio or a PC if you need more RAM than the Mini offers. You can get a similarly sized Mini PC from companies like Beelink or Minisforum with 32GB of RAM for pretty similar pricing to what Apple asks for a base model mini. They can often be upgraded to 64GB if you need more too.

The parts about Gb and GB did it for me. I thought that the SSDs with 10MBs speeds are well under Thunderbolt limits, I suppose that’s a bust.