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hajime

macrumors 604
Original poster
Jul 23, 2007
7,811
1,244
Hi, some mentioned that when MacOS runs out of memory, it uses the SSD as swap memory. If my Mac mini M2 base model has only 256GB SSD, how can I make MacOS to use the external SSD as swap memory?
 

jchurchill

macrumors member
Feb 15, 2021
54
61
The SSD on the M2 is incredibly fast. An external SSD wouldn't be able to match it, and could be 10x slower or worse, bringing your system to a crawl when it starts needing to use that swap. But if you really wanted to try it, the instructions at this link are very thorough and have been kept up to date.

 

Kelvinsin

macrumors newbie
Mar 4, 2023
23
10
The SSD on the M2 is incredibly fast. An external SSD wouldn't be able to match it, and could be 10x slower or worse, bringing your system to a crawl when it starts needing to use that swap. But if you really wanted to try it, the instructions at this link are very thorough and have been kept up to date.

Where to have the conclusion external ssd much slower than internal ssd?hmmm…
 

mavis

macrumors 601
Jul 30, 2007
4,737
1,453
Tokyo, Japan
Where to have the conclusion external ssd much slower than internal ssd?hmmm…
I thought that was common knowledge ... 🤔

Yeah, the internal SSD is significantly faster than most external SSD solutions. I've got a Sabrent Rocket 2TB NVMe drive connected through a Qwiizlab UH25 Pro dock/enclosure (USB 3.2 Gen 2), and it only hits about 900Mbps read/write. If I had a significantly more expensive enclosure (Thunderbolt 4, for example) I could get closer to the drive's max speed of 3000Mbps or so. Meanwhile, the M2 Mac mini's internal SSD writes at 3200Mbps and reads at about 3000Mbps - three times faster than my USB 3.2 Gen 2 dock.
 

Kelvinsin

macrumors newbie
Mar 4, 2023
23
10
I thought that was common knowledge ... 🤔

Yeah, the internal SSD is significantly faster than most external SSD solutions. I've got a Sabrent Rocket 2TB NVMe drive connected through a Qwiizlab UH25 Pro dock/enclosure (USB 3.2 Gen 2), and it only hits about 900Mbps read/write. If I had a significantly more expensive enclosure (Thunderbolt 4, for example) I could get closer to the drive's max speed of 3000Mbps or so. Meanwhile, the M2 Mac mini's internal SSD writes at 3200Mbps and reads at about 3000Mbps - three times faster than my USB 3.2 Gen 2 dock.
my acasis tbu405+980pro hit around 3000mbps but my 16gb m2 mini only hit 1500mbps, am i getting a fake apple?🤔
DiskSpeedTest.png
 
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hajime

macrumors 604
Original poster
Jul 23, 2007
7,811
1,244
My mini M2 base model has an average of 1500.8 MB/S write and 1506.6 MB/s read.
It's that slow because you've got the 256GB model. 512GB and higher is literally twice as fast - just Apple being Apple.

Is it true that for the M2 Mini, the 1TB version and 512GB version have the same SSD speed?
 
Last edited:

Rychiar

macrumors 68030
May 16, 2006
2,559
5,651
Waterbury, CT
buy a high quality SSD like the WD black 850x 4TB and put it in a 40gbps USB4 enclosure and it should be faster than the internal Mac mini memory and then ya can install your whole system on the external
 

Kelvinsin

macrumors newbie
Mar 4, 2023
23
10
It's that slow because you've got the 256GB model. 512GB and higher is literally twice as fast - just Apple being Apple.
If its model dependant means its not common knowledges, especially for newbie like us. Nevertheless, in my case or even 512gb model also not significant faster than external ssd. Its still depending what are the hardwares setup.
 

Yebubbleman

macrumors 603
May 20, 2010
5,832
2,421
Los Angeles, CA
Hi, some mentioned that when MacOS runs out of memory, it uses the SSD as swap memory. If my Mac mini M2 base model has only 256GB SSD, how can I make MacOS to use the external SSD as swap memory?

Boot from an external SSD. Pretty much your only option at this point.


The SSD on the M2 is incredibly fast. An external SSD wouldn't be able to match it, and could be 10x slower or worse, bringing your system to a crawl when it starts needing to use that swap. But if you really wanted to try it, the instructions at this link are very thorough and have been kept up to date.


While that article doesn't predate System Integrity Protection (SIP), it does predate macOS being on a signed/sealed system volume that is completely immutable by anything that isn't an Apple software update.
 

Ethosik

Contributor
Oct 21, 2009
7,821
6,725
I thought that was common knowledge ... 🤔

Yeah, the internal SSD is significantly faster than most external SSD solutions. I've got a Sabrent Rocket 2TB NVMe drive connected through a Qwiizlab UH25 Pro dock/enclosure (USB 3.2 Gen 2), and it only hits about 900Mbps read/write. If I had a significantly more expensive enclosure (Thunderbolt 4, for example) I could get closer to the drive's max speed of 3000Mbps or so. Meanwhile, the M2 Mac mini's internal SSD writes at 3200Mbps and reads at about 3000Mbps - three times faster than my USB 3.2 Gen 2 dock.
Yeah don’t say this stuff too loud. People are on a rampage about how massively slow these SSDs are on macs.
 

Ben J.

macrumors 6502a
Aug 29, 2019
675
362
Oslo
I saved a couple of hundred dollars on getting the 256 internal on my M2 mini. I used my money on a 2TB external NVMe in thunderbolt enclosure. Blackmagic scores: internal 1500MB/s - external 1300. Good bang for the buck if you know how to offload the internal to the external and use aliases/symlinks. I manage to keep 50% free space the internal, by having only system, apps, and essential files on it. 1300-1500MB speeds are plenty fast.
 

thebart

macrumors 6502
Feb 19, 2023
296
252
I saved a couple of hundred dollars on getting the 256 internal on my M2 mini. I used my money on a 2TB external NVMe in thunderbolt enclosure. Blackmagic scores: internal 1500MB/s - external 1300. Good bang for the buck if you know how to offload the internal to the external and use aliases/symlinks. I manage to keep 50% free space the internal, by having only system, apps, and essential files on it. 1300-1500MB speeds are plenty fast.
Which SSD and enclosure did you go with, if you don't mind saying?
 

ovbacon

Suspended
Feb 13, 2010
1,596
11,499
Tahoe, CA
On my Mac mini M2, 16GB/512GB, I run a Acasis Enclosure (TBU401E) with a Samsung 980 PRO 2TB and it tests in Blackmagic pretty steady at W:2800+ MB/s, R:2700+/- MB/s.
 

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eRondeau

macrumors 65816
Mar 3, 2004
1,166
392
Canada's South Coast
Besides the technical exercise of making it work, why would you ever want to do this? My "base" 8GB / 256GB M1 Mac Mini has been running for several days and it's used/using exactly 0 bytes of Swap memory. I worry about many things in life, but my swap memory usage is not among them.
 
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