3 ms·
Speed in MB/s HFS+ HFS+ Encrypted APFS APFS Encrypted 1M WRITE 1375 1373 1372 933 1M READ 2446 2340
by nrki 9y ago
Speed in MB/s
HFS+ HFS+ Encrypted APFS APFS Encrypted
1M WRITE 1375 1373 1372 933
1M READ 2446 2340 2162 1304
4K WRITE 852 797 502 378
4K READ 2106 1486 2156 1001
https://news.ycombinator.com/item?id=15333754 https://news.ycombinator.com/item?id=15333754
- mikeash 9y agoThat's really strange. Why would encryption affect APFS so badly but not HFS+?
- convivialdingo 9y agoLots of reasons. If crypto is part of the syscall path, then you definitely pay with latency. If you can push IO to a worker thread then you can release the user call faster. This also requires tuning the read-ahead cache more aggressively. It could also be a change in crypto algorithm, unaligned page IO, or any other overlooked IO latency problems.
- j45 9y agoAt a high level, I believe APFS encrypts files individually (and uniquely) instead of the whole drive. Have to do some more reading :)
- Someone 9y agoNot instead of, but optionally in addition to (https://developer.apple.com/library/content/documentation/FileManagement/Conceptual/APFS_Guide/Features/Features.html https://developer.apple.com/library/content/documentation/Fi...) On Mac OS, it seems you only get full disk encryption, though (https://arstechnica.com/gadgets/2017/09/macos-10-13-high-sierra-the-ars-technica-review/6/ https://arstechnica.com/gadgets/2017/09/macos-10-13-high-sie...)
- j45 9y agoAppreciate the clarification. Both are better than just one.
- zitterbewegung 9y agoThis was high sierra beta though.