I recently purchased a Sandisk Extreme V2 ssd and testing with AmorphousDiskMark it shows around 650 mb/s transfer rate only, when it is supposed to reach closer to 1000mb/s. Has anyone experienced the same? I am using the cable that came with the ssd, plugged directly into the MBA. Thanks
MacBook Air 13″, macOS 12.1
I have numerous SSDs ... Samsung, PNY, Crucial, OWC and etc. Not a single one has ever reached the hyped laboratory max transfer speeds. Some come close, but never actually to the max.
All my Samsung T7s work extremely well and have an advertised max of 1050 MBps read. Connected to a USB-A port they run at about 480 MBps. Connected to a USB-C/Thunderbolt 3 they run at 980-1020 MBps. All the others perform similarly.
To get top speed you have to have a properly rated cable attached to a port with matching speed capability.
I have numerous SSDs ... Samsung, PNY, Crucial, OWC and etc. Not a single one has ever reached the hyped laboratory max transfer speeds. Some come close, but never actually to the max.
All my Samsung T7s work extremely well and have an advertised max of 1050 MBps read. Connected to a USB-A port they run at about 480 MBps. Connected to a USB-C/Thunderbolt 3 they run at 980-1020 MBps. All the others perform similarly.
To get top speed you have to have a properly rated cable attached to a port with matching speed capability.
ku4hx wrote
..Connected to a USB-C/Thunderbolt 3 they run at 980-1020 MBps. All the others perform similarly.
You must have an Intel Mac or an old Thunderbolt3 dock. I never got any faster than 550-600 MBps out on my M1 MacBook Air or my OWC Thunderbolt 4 dock with my Samsung T7s.
Part of the issue with the M1 Macs is all the USB 3.x gen x devices that are connected to it only operate via a single lane. Actually, the Apple spec spells out:
but don't specify that the 3.1 is single lane and the T7, SanDisk Extreme and SanDisk Extreme Pro are specing their speeds with dual lane USBcontrollers. FWIW, I have seen some tests with USB4 enclosures that put their speeds equal to TB3 speeds, i.e. 2700-3000 MBps with M1 Macs.
Its the M1 - it has slower thunderbolt ports than intel Macs. My Sandisk Extreme V2 (4Tb) can get up to 700-800Mb sec reads/rights but still not 1000
It seems that all these new variations of USB specs are almost intentionally designed to confuse the consumer and to open up a wide area for manufacturers to make their wild speed claims even though those speeds might only be achieved with some very specific hardware platform. Then they take som originally named specs and then rename them to make people think they are getting something even newer. Here is a table that show that info:
I am sure once USB4 becomes more main stream, we will see even more of a mess! And this is actually a compacted listing that leaves out a couple additional variations.
Thanks for the response! I'm connecting it to the M1 MacBook Air directly into one of the two thunderbolt ports, using the cable that came with the SSD, which I'm guessing should be able to support the claimed 1000mb/s as it was included in the package, but could be wrong. Just thought the M1 Macs are pretty new still so should have all the latest usb technology , yet it seems there is a bottleneck when it comes to external ssds.
Thanks for sharing this info! Could you direct me to official documentation where this is stated? Makes you wonder what exactly they tested the port on to make their claims of 40Gb/s or 10Gb/s. More likely they just copied those numbers off of the technology spec sheets without real world testing anything.
Hi ku4hx, I forgot to ask, what MacBook are you using with the performance you mentioned on those ssds? Thanks.
Sandisk Extreme V2 ssd not reaching advertised 1000mbps on M1 MacBook Air Monterey
