I just replaced the 128GB SSD that originally came in my Macbook Air. I believe it is a Samsung SSUAX. I decided to get a bigger drive to start dual-booting, try some VMs, etc. I didn't want to go the nVME route as I would have lost deep sleep, so I got a second-hand SSUBX 256GB SSD from a 2015 Macbook Pro I believe. It only set me back £38 on eBay so I thought, worth a shot.
All I can say is - wow! Previously, I was getting about 400-450MBps read speeds, and 700-750 MBps write speeds. With the new drive, it's jumped to 1100-1200 MBps reads, and 1350-1450 MBps writes. I expected a performance increase from the bigger capacity and the faster SSD controller, but not really as much as this! Highly recommend this upgrade for anyone in a similar position!
All I can say is - wow! Previously, I was getting about 400-450MBps read speeds, and 700-750 MBps write speeds. With the new drive, it's jumped to 1100-1200 MBps reads, and 1350-1450 MBps writes. I expected a performance increase from the bigger capacity and the faster SSD controller, but not really as much as this! Highly recommend this upgrade for anyone in a similar position!