I created a 30GB HFS+ formatted Ramdisk and checked the pace of copying a big file to it utilizing
pv. What shocked me was that the pace was about the identical as an area copy on the identical disk (truly, barely decrease, even!):
✦ ❯ pv ~/2017.user-dir.tgz > ~/tmp.dat ^C.4GiB 0:00:22 [2.67GiB/s] [===============================================> ] 61% ETA 0:00:13
✦ ❯ pv ~/2017.user-dir.tgz > /Volumes/RamDisk/take a look at.dat 27.6GiB 0:00:12 [2.23GiB/s] [=====================>
I would have assumed that writing to the ramdisk would be on par with the read speed of the SSD (with some overhead due to the file system), but nowhere near this! Any good explanation?