Looks like a thorough analysis, but I question the use of "bs=1m". Author says they verified that "dd was correctly only using a one meg buffer", but "bs" is m

Looks like a thorough analysis, but I question the use of "bs=1m". Author says they verified that "dd was correctly only using a one meg buffer", but "bs" is more than just a buffer, it's the "count" that read()s are issued in. As in "read(fd, 1000000);" for the syscall. I don't know about MacOS, but in the distant past I found that using larger "bs" values tended to cause my Linux machines to behave sluggishly, particularly when interacting with very slow media like USB sticks or SD cards. I tend to use "bs=32k" at the largest because it offers good performance while also limiting sluggishness. Using too small a value limits throughput because you spend so much time issuing read() calls and looping. I'm sure the author isn't going to set up that environment again just to run a test, but it would be interesting to know if a smaller bs value would have had any change in this environment.