MacBook or iMac, is there any speed difference between that 256GB, 512GB and 1TB options? And what about SSD endurance, does it differ in any way?


Assuming that you're talking about SSDs within the same generations of Mac, then capacity has no bearing on the speed, quality and/or expected lifespan of the components being used.

For example, the 1TB, 2TB and 4TB options of SSDs in an iMac Pro are the same as each other in terms of quality and performance. Likewise for the various SSD options in current models of 15" MacBook Pro and so on.

Where you will see differences are when you're comparing different drives, either because they're in different generations (or even types) of Mac models (e.g. 13" MBP v 15" MBP) or because they're a different type of storage device (e.g. traditional v fusion v solid state drives).

| improve this answer | |
  • I'm asking because apparently some people report different speeds here: 2080 write and 2383 read for 512GB vs. 1400MB/s write and 2100MB/s read for 256GB. – jimmy Jul 22 '18 at 17:42
  • Ok, well, there are a number of factors that will affect real life transfer speeds, but all things remaining equal should result in similar transfer speeds regardless of disk size. The only real advantage of more disk space from a speed perspective is that you're less likely to run low on space which can have a speed impact if/when you're low on RAM, as macOS can make more use of it. The various results you're seeing in the macrumors forum isn't all that surprising because you've got different users sharing their results, so none of these are in a controlled environment. – Monomeeth Jul 23 '18 at 0:53
  • For example, you'll always get better transfer speeds when transferring 1 x 5GB file as compared to transferring 500 x 10MB files (even though the overall amount of data being transferred is very similar). What other processes are running will also impact things, as will a user's software/hardware setup generally. My advice would be to get the largest size SSD you can afford, so long as you're allowing enough $ for external backup drives etc. Many will see the 512GB size as the sweet spot, but that's very subjective. – Monomeeth Jul 23 '18 at 0:53
  • Hmm.... do you know of any benchmarks to support your explanations? Because I found another "evidence" that different sizes result in different performance, 960 EVO and 960 Pro. – jimmy Jul 23 '18 at 9:03
  • I assume you’re talking about the different data transfer rates of the 256GB v 512GB Samsung 950 Pro series? Obviously I can’t comment on that specific series, nor how the tests were carried out, but I do note that in the other cases the size of SSDs do not seem to impact transfer speeds greatly, although there’s no Apple SSDs being tested. – Monomeeth Jul 23 '18 at 10:19

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .