Why is my SATA drive running at 728 megabytes per second if the real-world limit is 600 megabytes per second?

Question

According to this answer it should not be performing like this but here it is doing exactly that!

dd could be skipping zeroed or TRIMed areas of disk. What kind of disk are you copying from or to? Otherwise it could be using caching: https://unix.stackexchange.com/questions/691372/dd-faster-than-it-should-be — Mokubai, Jan 01 '24 at 17:47
please do not post a picture of text ... copy and paste the text instead — jsotola, Jan 01 '24 at 17:47
What kind of SATA drive is this? (Specifically, why does it say "non-tried: 9223 petabytes")? — u1686_grawity, Jan 01 '24 at 18:02

score 3 · Answer 1 · edited Jan 01 '24 at 23:30

3

It was BTRFS compression.

And since I was writing all zeros 3.5 TiB of zeros compressed to around 90 GiB and the actual throughput was significantly lower than I was lead to believe by the performance metrics.

edited Jan 01 '24 at 23:30

Giacomo1968

55,001

answered Jan 01 '24 at 23:11

FennecTECH

47

1

Great self-solved answer! – Giacomo1968 Jan 02 '24 at 00:27

Why is my SATA drive running at 728 megabytes per second if the real-world limit is 600 megabytes per second?

1 Answers1

It was BTRFS compression.