How to choose a fast file system on laptop + SSD?

[Zesko]

This benchmark is old, but it is not in a real world use.

See my current benchmark results with Kernel 5.18+ and my dual Nvme SSDs: (Both have Btrfs partition and Ext4 partition)

• Read benchmark using cat

Btrfs slow read/write speed on nvme

kdiskmark using fio benchmark isn’t in a real world scenario. I checked cat for reading a large game data 7z 30 GB in two different partitions (Ext4 and Btrfs) in the same Nvme SSD. Open bash shell in terminal: Btrfs $ time cat Game.7z > /dev/null real 0m18,430s user 0m0,045s sys 0m10,223s 18 sec reading is done Ext4 $ time cat Game.7z > /dev/null real 0m28,873s user 0m0,053s sys 0m12,955s 28 sec reading is done However I don’t understand why.

Btrfs slow read/write speed on nvme

In my other device: Btrfs and ext4 in the same nvme SSD without LUKS Btrfs $ time cat Game.7z > /dev/null real 0m10,877s user 0m0,042s sys 0m8,518s Ext4 $ time cat Game.7z > /dev/null real 0m13,300s user 0m0,029s sys 0m7,446s

• Copy benchmark

Btrfs slow read/write speed on nvme

Here is my last copy benchmark: I have two Nvme SSDs, each SSD has Btrfs and Ext4. Btrfs: Copying the game “Dota 2” directory without archive from Btrfs SSD A to Btrfs SSD B $ time cp -r "~/Desktop/dota 2 beta" /run/media/zesko/Backup/dota2_backup real 0m33,970s user 0m0,117s sys 0m26,751s Ext4 Copying the same game directory from Ext4 SSD A to Ext4 SSD B $ time cp -r "/media/Steam/steamapps/common/dota 2 beta" ~/VMs/dota2_backup real 0m39,838s user 0m0,105s sys …

• Copy benchmark: Btrfs has the deduplication ability, Ext4 does not.

Btrfs slow read/write speed on nvme

Copying benchmark in a real world using cp. Let check: Copying the Game data 30 GB in the same filesystem Ext4: $ time cp Game.7z Game1.7z real 0m24,201s user 0m0,001s sys 0m21,379s Btrfs: $ time cp Game.7z Game1.7z real 0m0,011s user 0m0,001s sys 0m0,003s Btrfs: copying the data from subvolume to another subvolume: (Linux Kernel 5.17+ improved deduplication) $ time sudo cp Game.7z /opt/Game1.7z real 0m2,141s user 0m0,038s sys 0m0,016s Btrfs takes no …

Linux Kernel 6.1 in the future:

Btrfs slow read/write speed on nvme

A short info: Linux Kernel 6.1 supports Btrfs async buffered writes, which improves write performance a lot.

https://lore.kernel.org/linux-btrfs/cover.1664798047.git.dsterba@suse.com/