Why are macbook air M4 2025 external crucial P510 m2 2TB ssd speed slow in Tahoe as well as others nvmes not achieving speeds. Why?
Tried with 40gbps and 10gbps enclosures. Tried anamorphic and Black Magic Disk speed and not achieving even 1/2 of the speeds with various crucial p510 Nvme, 990 pro and more with anamorphus and Black Magic. Anyone getting this?
Can Apple help pls.
MacBook Air 13″
Crucial claims that the P510 SSDs have speeds "up to 11,000 MB/s" (read) and "up to 9,500 MB/s" (write).
https://www.crucial.com/ssd/p510/CT1000P510SSD8
Ignoring the issue of whether the SSDs can actually sustain these speeds, these translate into "up to 88,000 Mb/s" (read) and "up to 76,000 Mb/s" (write). Thunderbolt 3 and USB 4 40 Gbps have a maximum bandwidth of 40,000 Mb/s before overhead, and there will definitely be various types of overhead. A 10 Gbps enclosure has a maximum bandwidth of 10,000 Mb/s before overhead.
There is no way you are going to get 88,000 Mb/s or 76,000 Mb/s of sustained transfer when there is an interface limiting sustained speeds to less than 40,000 Mb/s or less than 10,000 Mb/s.
Those SSDs are meant for internal M.2 PCIe sockets – or perhaps for Thunderbolt 5 enclosures which would have the ability to dedicate 80,000 Mb/s (before overhead) to data transfer. (The M4 MacBook Air does not support Thunderbolt 5 and would not be able to take advantage of the higher theoretical maximum data transfer speeds of such enclosures.)
Crucial claims that the P510 SSDs have speeds "up to 11,000 MB/s" (read) and "up to 9,500 MB/s" (write).
https://www.crucial.com/ssd/p510/CT1000P510SSD8
Ignoring the issue of whether the SSDs can actually sustain these speeds, these translate into "up to 88,000 Mb/s" (read) and "up to 76,000 Mb/s" (write). Thunderbolt 3 and USB 4 40 Gbps have a maximum bandwidth of 40,000 Mb/s before overhead, and there will definitely be various types of overhead. A 10 Gbps enclosure has a maximum bandwidth of 10,000 Mb/s before overhead.
There is no way you are going to get 88,000 Mb/s or 76,000 Mb/s of sustained transfer when there is an interface limiting sustained speeds to less than 40,000 Mb/s or less than 10,000 Mb/s.
Those SSDs are meant for internal M.2 PCIe sockets – or perhaps for Thunderbolt 5 enclosures which would have the ability to dedicate 80,000 Mb/s (before overhead) to data transfer. (The M4 MacBook Air does not support Thunderbolt 5 and would not be able to take advantage of the higher theoretical maximum data transfer speeds of such enclosures.)
With NVME and DIY enclosures, the paring can be very critical in terms of the performance you can achieve. Not all pairings play well with all computers or operating systems. Some are just slow, or unreliable or even simply do not work. You should verify that the combinations you are using are recommended by the manufacturer of the enclosures or do an internet search for some one who has tested those enclosures with various devices,
FWIW, I have a Sabrent USB3.2, 10GB enclosure paired with a Samsung 980 PRO and get an average 800-850 megabytes/second with a mix of large and small files. As stated, the theoretical limit will never be achieved (1250 megabytes/second) due to USB transfer over head itself, operating system, and the fact that it shares band width with everything else on the USB bus.
As far as Thunderbolt 3/4 or USB 4 devices, they will max out at 3200 -3900 megabytes/second and maybe a touch more depending on the Mac it is connected to. You will never get the 5000 megabyte/second theoretical on any computer. I have both types of devices and that is the range I see. When connected to my M1 MacBook Air the rates are on the slower end and when connected to my M4 MacBook Air they are on the higher end.
External NVME M2 gen4 and gen5 speeds not being achieved. Why?
