The way NAND storage chips are made, there will also be a performance difference between their various capacities. The lower the capacity, the slower the NAND chip will perform. So, it was not particularly surprising when it was already revealed that the 32GB iPhone 7 has slower storage than the 256GB or even 128GB iPhone 7 variants.
However, what has turned out to be surprising is just how slow it is. A video posted on Unbox Therapy by Lewis Hilsenteger shows just how slow storage on the 32GB iPhone 7 is compared to the 256GB variant.
In one of the benchmarks, the read storage performance of the 32GB iPhone 7 was a respectable 686MB/s vs. 856MB/s on the 256GB iPhone 7. However, it was the low write speed of 42MB/s that is the cause of concern here. For comparison, the 256GB iPhone 7 was 8x times faster with a write speed of 341MB/s.
The slower write speed is something that most iPhone 7 owners are going to notice when they copy large files from their PC to their handset. As an iTunes transfer test done by Lew shows, it took more than a minute extra to copy a 4.2GB Star Wars movie file to the internal storage of the 32GB iPhone 7 than its 256GB counterpart. The 128GB iPhone 7 does not suffer from any such serious performance issues.
Are you disappointed that the 32GB iPhone 7 comes with significantly slower NAND storage than its higher storage variants?