Check out some of the reviews on Amazon. Some reported the same, and it seems it might depends on the implementation of the USB 3 SD card reader in the laptop (MacBook in this case). Is your MBP a 14/16" or a 13"?Just bought Jetrdive Lite 330 512GB for MBP M1, to store downloaded junk that I ocassionaly still need to go through (I am lazy in cleaning up such stuff), it was pretty cheap (around 80$). But with Blackmagic test the write speed on mine is 35MB/s (read is 85MB/s) straight out of the box... Any ideas why such difference to the one in test? It is formatted as exFAT...