2019 MacBook Air
Using the Blackmagic Disk Speed test, the read speeds of the SSD are slower. It found write speeds of 1GB/s and read speeds of 1.3GB/s. Meanwhile the 2018 MacBook Air had write speeds of 920MB/s and read speeds of 2GB/s.
The read and write speeds of the 128GB model were similar to 2018’s equivalent model, with write speeds of 500MB/s and read speeds of 1.3GB/s. Models with higher capacity SSDs weren’t tested. The slower speeds could be a result of Apple lowering the price of the 2019 MacBook Air.