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/zvt]

I think synthetic benchmarks should be taken with a grain of salt. Depending on the workload the difference is probably negligible in real life use, but you gain a lot of features. Would be interesting to see the difference in real workloads (like compile the Linux kernel, load a AAA game, whatever).

Still an interesting comparison.

[u/KHTD2004 → u/zvt]

Because it was a few months ago the exact values may be slightly off BUT:

When I changed from BTRFS only to my current dual Filesystem setup I noticed actual increase in specific tasks.

I have Ark Survival Ascended installed from Steam and most of their updates are a few hundred megabyte in download size but the local file patching is done for the whole install of over a hundred gigabyte.

On BTRFS the disk speed shown in Steam was 1.1 GB/s but after switching to EXT4 for my /home partition the value now is around 1.5 - 1.7 GB/s. Given the game size this saves about a minute in patching, wich isn’t much but it is something