Speed test of Samsung external SSDs: T1, T3 and T5

I just bought my 4th external USB3 SSD for my MacBookPro. I obviously don’t use all of them together, I just was just constructing my latest external Sockle storage bay. This time it’s a 1TB SSD and it’s a generation T5. So this was a good moment to compare it to my previous T1 and T3 SSD drives. I use the Blackmagic Disk Speed Test app to get realistic read and write data transfer rates. I will round them off to the nearest multiple of 10MB/s.

Benchmark: internal 500GB SSD

We will compare all the disks with the performance of the internal SSD disk, which has a SATA-III connection (not the slower USB 3 connection): 560 MB/s write – 720 MB/s read speed.


The T1 generation of SSD (in my case a 500GB) is the slowest: 260 MB/s write and 360 MB/s
  The T3 generation of SSD (I have 2 x 500GB ones) is a bit faster: 360 MB/s write and 400 MB/s read speed.
The last T5 generation of SSD (in my case a 1TB one) is the fastest: 420 MB/s write and 420 MB/s read speed. This is about 66% or 2/3 of the theoretical maximum transfer speed of USB3: 5Gbps or 625 MB/s

EXTERNAL HD: Lacie Porsche 1TB 2.5″ ‘classic’ hard drive

Just to get a feel of just how much better that is than the old ‘rotating magnetic’ disks: the speed of a brand new 2.5″ 1TB Lacie Porsche disk: 130 MB/s read and write speed. That is 1/3 of the speed of the Samsung T5 SSD, at about 1/4 of the cost (1TB: 100 euro vs 420 euro – Nov 2017).


INTERNAL SSD (500GB) 560MB/s 710MB/s
EXTERNAL SSD (500GB T1) 260MB/s 360MB/s
EXTERNAL SSD (500GB T3) 360MB/s 400MB/s
EXTERNAL SSD (1000GB T5) 420MB/s 420MB/s
EXTERNAL HD (2TB Lacie Porsche) 130MB/s 130MB/s

3 thoughts on “Speed test of Samsung external SSDs: T1, T3 and T5”

  1. Hi Peter, does your MacBook Pro have USB 3.0 or USB 3.1? This makes a difference to some of us with older hardware.

      1. …or what they used to call USB 3.0, which is what I’ve got. Your comparison to the external HD was also very helpful. Thanks!

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