#btrfs

compression

the way i did this was by creating 4 virtual disk images, one with each of the following mount options: compress=zstd, compress-force=zstd, compress=zstd:10, and compress-force=zstd:10. i then copied the same files to each one and checked data saving with compsize

results: the difference in compression between zstd and zstd:10 was negligible. the difference between using compress and compress-force was present, but it only helped with binaries and some videogames

most of the data in your drives is already compressed! and for anything that isnt, btrfs is pretty good at figuring out if it should compress it or not

speed

this was measured with KDiskMark, by testing the speeds of one of my SSD's while mounted with different compression options. these were: compress=no, compress=zstd, compress-force=zstd and compress-force=zstd:10

with my computer at idle:

compression gave better write speeds, but forcing it diminished this due to wasted cpu cycles

compress=zstd gave faster random read speeds

everything else was the same

with my computer under load:

in order to check how compression performs while the cpu is under load, i disabled 6 of my 8 threads and used stress-ng to stress the remaining 2

in this case compression gave worse sequential writes, but not by much

also slightly better sequential reads

random reads were way worse with compression

conclusion

you should use compress=zstd. it performs better with everything, unless writing under heavy loads. if you have a bad cpu then you may consider not using compression