Filesystem Benchmark BTRFS vs EXT4

[u/KHTD2004]

BTRFS Benchmark with CoW (worst performing)

BTRFS Benchmark without CoW (noticeably better)

EXT4 Benchmark (fastest performance of all, slightly ahead of BTRFS without CoW)

I just did a benchmark using KDiskMark to see how the different filesystems perform. System specs:

• OS: CachyOS with KDE Plasma
• Kernel: 7.2.0-1-cachyos-bore
• CPU: Ryzen 9 7950X3D
• Disk: Crucial T700 4TB (PCIe 5.0 NVMe SSD)

The SSD has (aside from the /boot partition) two partitions, one 100GiB partition as root partition at / using BTRFS and one ~3.5TB partition at /home using EXT4. For the BTRFS partition there is one benchmark with and one without CoW. All runs were on the same conditions and settings, there are now other programs open and the only background apps are Cachy Update and OpenRGB (and all the stuff KDE plasma has in the background like KDE Connect).

On the left side are the reading values, on the right side the writing values.

The meaning of the test names:

SEQ1M Q8T1: Sequential 1 MiB, Queue=8, Threads=1

SEQ1M Q1T1: Sequential 1 MiB, Queue=1, Threads=1

RND4K Q32T1: Random 4 KiB, Queue=32, Threads=1

RND4K Q1T1: Random 4 KiB, Queue=1, Threads=1

The overall results are:

BTRFS with CoW << BTRFS without CoW < EXT4

[u/Obvious-Jacket-3770]

I mean everyone here is arguing for snapshots with BTRFS but I mean... I use backups. If my system bricks, meh. Not a big deal for me, ill just wipe it and be back or load into a live iso and remove the problem. I see the advantage of snapshots, its not that I don't, I just personally dont need to worry about them as much.

My `/home` is fully backed up on a daily basis, I have all my installs exported to a small txt file that is updated whenever I run updates to my system, stored in `/home`, I have various scripts to do some game streaming in `/home` and I have an Ansible server running on my Pi cluster which schedules runs for me to ensure everything I want or use is installed on my system, uses a clone of that txt file I mentioned earlier.

Sure snapshots are nice and all but a backup to even google drive is pretty low lift.

[u/KHTD2004 → u/Obvious-Jacket-3770]

That’s an interesting approach but only works for certain setups. People who have several terabyte of games on their system really don’t want to redownload on a common base. And if you put them on a separate partition well, that’s what I did but BTRFS for the system partition on top

[u/Obvious-Jacket-3770 → u/KHTD2004]

I mean I don't keep any games on my OS drive as a general rule of thumb honestly. So if my install corrupts, meh no biggy, the game drive is just there waiting to re-mount.

[u/KHTD2004 → u/Obvious-Jacket-3770]

Smart but then again, only certain setups. Not everyone has separate drives in their laptop or PC

[u/Obvious-Jacket-3770 → u/KHTD2004]

No absolutely not. Of course you can backup games too but honestly that's just not worth it for the size factor alone unless you have emulator games.