2 ms·
"As for disk speed, dd if=/dev/zero of=/tmp/output bs=128k count=50k; rm -f /tmp/output reports 1.6 GB/s which is 3.6x slower than my Mac Studio, and 3x slower
by discordance 3y ago
"As for disk speed, dd if=/dev/zero of=/tmp/output bs=128k count=50k; rm -f /tmp/output reports 1.6 GB/s which is 3.6x slower than my Mac Studio, and 3x slower than my Intel (which has the same M.2 stick). I'm told that Intel and Apple are just better at this, but I wish I understood why. "
Can anyone here answer why this is?
- pstrateman 3y agoApple made fsync a noop. You have to make a different call to get sync on macos. So tons is stuff is faster because it's not actually writing to disk.
- bishfish 3y agoPlus he isn’t using oflag=direct, so since output file is small it isn’t even making it to disk. I think it would only be sent to page cache. I’m afraid he is testing CPU and memory (bus) speeds here. oflag=direct will write direct and bypass page cache.