According to French website Consomac, they ran some testing on the 2019 MacBook Air using the blackmagic Disk Speed benchmarking tool, and based on their findings, it seems that the latest MacBook Air model actually has a slower SSD compared to its 2018 predecessor. It featured write speeds of up to 1GB/s and read speeds of 1.3GB/s.
This is versus 2018’s model where it had write speeds of 920MB/s and read speeds of 2GB/s. While the write speeds have improved, the read speeds are the ones that seem to have taken quite a hit in performance. Given that read speeds are important when it comes to accessing files and also booting up the laptop, this can have a noticeable impact on the user’s experience.
We should note that the model they tested was the 256GB model and that your mileage may vary depending on the configuration you chose. It is unclear why the SSDs are slower, but it is possible that Apple could have opted for a cheaper SSD model in order to bring prices down. Whether or not you’ll be able to feel the difference depends on how you use your laptop, but it’s something to consider.