This page contains the raw measurements.
Benchmark results on a Raspberry Pi Zero 2W running Ubuntu 24.04 (noble) arm64
on 2024-06-05:
$ ls -l /boot/initrd.img*
lrwxrwxrwx 1 root root 27 Jun 4 06:50 /boot/initrd.img -> initrd.img-6.8.0-1005-raspi
-rw-r--r-- 1 root root 52794656 Jun 4 18:29 /boot/initrd.img-6.8.0-1005-raspi
$ 3cpio -t /boot/initrd.img | wc -l
2534
$ hyperfine -p "rm -rf initrd" "3cpio -x /boot/initrd.img -C initrd" "unmkinitramfs /boot/initrd.img initrd" --export-markdown extract.md
Benchmark 1: 3cpio -x /boot/initrd.img -C initrd
Time (mean ± σ): 5.075 s ± 0.247 s [User: 0.116 s, System: 1.932 s]
Range (min … max): 4.631 s … 5.591 s 10 runs
Benchmark 2: unmkinitramfs /boot/initrd.img initrd
Time (mean ± σ): 173.847 s ± 8.368 s [User: 31.155 s, System: 269.939 s]
Range (min … max): 162.180 s … 183.792 s 10 runs
Summary
3cpio -x /boot/initrd.img -C initrd ran
34.25 ± 2.34 times faster than unmkinitramfs /boot/initrd.img initrd
| Command |
Mean [s] |
Min [s] |
Max [s] |
Relative |
3cpio -x /boot/initrd.img -C initrd |
5.075 ± 0.247 |
4.631 |
5.591 |
1.00 |
unmkinitramfs /boot/initrd.img initrd |
173.847 ± 8.368 |
162.180 |
183.792 |
34.25 ± 2.34 |
$ hyperfine --warmup 1 "3cpio -t /boot/initrd.img" "lsinitramfs /boot/initrd.img" -u second --export-markdown list.md
Benchmark 1: 3cpio -t /boot/initrd.img
Time (mean ± σ): 0.697 s ± 0.003 s [User: 0.039 s, System: 0.265 s]
Range (min … max): 0.692 s … 0.703 s 10 runs
Benchmark 2: lsinitramfs /boot/initrd.img
Time (mean ± σ): 165.425 s ± 7.986 s [User: 30.696 s, System: 259.767 s]
Range (min … max): 154.661 s … 176.996 s 10 runs
Summary
3cpio -t /boot/initrd.img ran
237.45 ± 11.51 times faster than lsinitramfs /boot/initrd.img
| Command |
Mean [s] |
Min [s] |
Max [s] |
Relative |
3cpio -t /boot/initrd.img |
0.697 ± 0.003 |
0.692 |
0.703 |
1.00 |
lsinitramfs /boot/initrd.img |
165.425 ± 7.986 |
154.661 |
176.996 |
237.45 ± 11.51 |
Benchmark results on a desktop machine with an AMD Ryzen 7 5700G running Ubuntu
24.04 (noble) on 2024-06-09. The tests were done in chroots that use overlayfs
on tmpfs for writes.
$ schroot-wrapper -p initramfs-tools,linux-image-generic,zstd,busybox-initramfs,cryptsetup-initramfs,kbd,lvm2,mdadm,ntfs-3g,plymouth,plymouth-theme-spinner,hyperfine -u root -c noble
(noble)root@desktop:~# ls -l /boot/initrd.img*
lrwxrwxrwx 1 root root 27 Jun 4 23:37 /boot/initrd.img -> initrd.img-6.8.0-35-generic
-rw-r--r-- 1 root root 70220742 Jun 4 23:37 /boot/initrd.img-6.8.0-35-generic
(noble)root@desktop:~# 3cpio -t /boot/initrd.img | wc -l
2097
(noble)root@desktop:~# 3cpio -e /boot/initrd.img
0 cpio
77312 cpio
8033792 cpio
51411456 zstd
(noble)root@desktop:~# hyperfine -p "rm -rf initrd" "3cpio -x /boot/initrd.img -C initrd" "unmkinitramfs /boot/initrd.img initrd" --export-markdown extract.md
Benchmark 1: 3cpio -x /boot/initrd.img -C initrd
Time (mean ± σ): 107.2 ms ± 1.0 ms [User: 3.8 ms, System: 91.9 ms]
Range (min … max): 105.8 ms … 110.2 ms 27 runs
Benchmark 2: unmkinitramfs /boot/initrd.img initrd
Time (mean ± σ): 6.698 s ± 0.026 s [User: 5.106 s, System: 5.639 s]
Range (min … max): 6.648 s … 6.724 s 10 runs
Summary
3cpio -x /boot/initrd.img -C initrd ran
62.48 ± 0.62 times faster than unmkinitramfs /boot/initrd.img initrd
| Command |
Mean [ms] |
Min [ms] |
Max [ms] |
Relative |
3cpio -x /boot/initrd.img -C initrd |
107.2 ± 1.0 |
105.8 |
110.2 |
1.00 |
unmkinitramfs /boot/initrd.img initrd |
6697.5 ± 25.6 |
6647.8 |
6723.6 |
62.48 ± 0.62 |
(noble)root@desktop:~# hyperfine --warmup 1 "3cpio -t /boot/initrd.img" "lsinitramfs /boot/initrd.img" --export-markdown list.md
Benchmark 1: 3cpio -t /boot/initrd.img
Time (mean ± σ): 42.9 ms ± 0.5 ms [User: 1.7 ms, System: 13.9 ms]
Range (min … max): 42.0 ms … 43.9 ms 68 runs
Benchmark 2: lsinitramfs /boot/initrd.img
Time (mean ± σ): 6.471 s ± 0.041 s [User: 5.054 s, System: 5.323 s]
Range (min … max): 6.408 s … 6.536 s 10 runs
Summary
3cpio -t /boot/initrd.img ran
150.68 ± 1.88 times faster than lsinitramfs /boot/initrd.img
| Command |
Mean [ms] |
Min [ms] |
Max [ms] |
Relative |
3cpio -t /boot/initrd.img |
42.9 ± 0.5 |
42.0 |
43.9 |
1.00 |
lsinitramfs /boot/initrd.img |
6471.0 ± 41.0 |
6408.1 |
6536.3 |
150.68 ± 1.88 |
$ schroot-wrapper -p initramfs-tools,linux-image-generic,zstd,busybox-initramfs,cryptsetup-initramfs,kbd,lvm2,mdadm,ntfs-3g,plymouth,plymouth-theme-spinner,hyperfine -u root -c jammy
(jammy)root@desktop:~# ls -l /boot/initrd.img*
lrwxrwxrwx 1 root root 29 Jun 4 23:49 /boot/initrd.img -> initrd.img-5.15.0-107-generic
-rw-r--r-- 1 root root 112100650 Jun 4 23:50 /boot/initrd.img-5.15.0-107-generic
(jammy)root@desktop:~# 3cpio -t /boot/initrd.img | wc -l
3789
(jammy)root@desktop:~# 3cpio -e /boot/initrd.img
0 cpio
77312 cpio
8033792 zstd
(jammy)root@desktop:~# hyperfine -p "rm -rf initrd" "3cpio -x /boot/initrd.img -C initrd" "unmkinitramfs /boot/initrd.img initrd" --export-markdown extract.md
Benchmark 1: 3cpio -x /boot/initrd.img -C initrd
Time (mean ± σ): 455.1 ms ± 3.6 ms [User: 10.7 ms, System: 263.4 ms]
Range (min … max): 451.5 ms … 464.5 ms 10 runs
Benchmark 2: unmkinitramfs /boot/initrd.img initrd
Time (mean ± σ): 2.217 s ± 0.008 s [User: 0.878 s, System: 2.264 s]
Range (min … max): 2.198 s … 2.227 s 10 runs
Summary
'3cpio -x /boot/initrd.img -C initrd' ran
4.87 ± 0.04 times faster than 'unmkinitramfs /boot/initrd.img initrd'
| Command |
Mean [ms] |
Min [ms] |
Max [ms] |
Relative |
3cpio -x /boot/initrd.img -C initrd |
455.1 ± 3.6 |
451.5 |
464.5 |
1.00 |
unmkinitramfs /boot/initrd.img initrd |
2216.5 ± 8.3 |
2198.2 |
2227.3 |
4.87 ± 0.04 |
(jammy)root@desktop:~# hyperfine --warmup 1 "3cpio -t /boot/initrd.img" "lsinitramfs /boot/initrd.img" --export-markdown list.md
Benchmark 1: 3cpio -t /boot/initrd.img
Time (mean ± σ): 336.0 ms ± 6.3 ms [User: 5.5 ms, System: 77.8 ms]
Range (min … max): 326.5 ms … 345.0 ms 10 runs
Benchmark 2: lsinitramfs /boot/initrd.img
Time (mean ± σ): 1.374 s ± 0.010 s [User: 0.725 s, System: 1.050 s]
Range (min … max): 1.354 s … 1.393 s 10 runs
Summary
'3cpio -t /boot/initrd.img' ran
4.09 ± 0.08 times faster than 'lsinitramfs /boot/initrd.img'
| Command |
Mean [ms] |
Min [ms] |
Max [ms] |
Relative |
3cpio -t /boot/initrd.img |
336.0 ± 6.3 |
326.5 |
345.0 |
1.00 |
lsinitramfs /boot/initrd.img |
1374.3 ± 10.3 |
1354.0 |
1392.9 |
4.09 ± 0.08 |
$ schroot-wrapper -p initramfs-tools,linux-image-generic,firmware-linux,zstd,cryptsetup-initramfs,lvm2,kbd,mdadm,ntfs-3g,plymouth,console-setup,hyperfine -u root -c bookworm
(bookworm)root@desktop:~# ( cd /boot && ln -s initrd.img-* initrd.img )
(bookworm)root@desktop:~# ls -l /boot/initrd.img*
lrwxrwxrwx 1 root root 25 Jun 9 15:55 /boot/initrd.img -> initrd.img-6.1.0-21-amd64
-rw-r--r-- 1 root root 62448197 Jun 9 15:53 /boot/initrd.img-6.1.0-21-amd64
(bookworm)root@desktop:~# 3cpio -t /boot/initrd.img | wc -l
2935
(bookworm)root@desktop:~# 3cpio -e /boot/initrd.img
0 zstd
(bookworm)root@desktop:~# hyperfine -p "rm -rf initrd" "3cpio -x /boot/initrd.img -C initrd" "unmkinitramfs /boot/initrd.img-6.1.0-21-amd64 initrd" --export-markdown extract.md
Benchmark 1: 3cpio -x /boot/initrd.img -C initrd
Time (mean ± σ): 267.5 ms ± 2.4 ms [User: 7.6 ms, System: 209.0 ms]
Range (min … max): 264.8 ms … 273.2 ms 10 runs
Benchmark 2: unmkinitramfs /boot/initrd.img-6.1.0-21-amd64 initrd
Time (mean ± σ): 1.362 s ± 0.004 s [User: 0.681 s, System: 1.513 s]
Range (min … max): 1.355 s … 1.368 s 10 runs
Summary
'3cpio -x /boot/initrd.img -C initrd' ran
5.09 ± 0.05 times faster than 'unmkinitramfs /boot/initrd.img-6.1.0-21-amd64 initrd'
| Command |
Mean [ms] |
Min [ms] |
Max [ms] |
Relative |
3cpio -x /boot/initrd.img -C initrd |
267.5 ± 2.4 |
264.8 |
273.2 |
1.00 |
unmkinitramfs /boot/initrd.img-6.1.0-21-amd64 initrd |
1361.7 ± 4.4 |
1354.6 |
1368.4 |
5.09 ± 0.05 |
(bookworm)root@desktop:~# hyperfine --warmup 1 "3cpio -t /boot/initrd.img" "lsinitramfs /boot/initrd.img-6.1.0-21-amd64" --export-markdown list.md
Benchmark 1: 3cpio -t /boot/initrd.img
Time (mean ± σ): 210.0 ms ± 2.3 ms [User: 4.8 ms, System: 66.2 ms]
Range (min … max): 207.1 ms … 214.7 ms 14 runs
Benchmark 2: lsinitramfs /boot/initrd.img-6.1.0-21-amd64
Time (mean ± σ): 571.8 ms ± 1.9 ms [User: 515.7 ms, System: 496.8 ms]
Range (min … max): 568.7 ms … 574.5 ms 10 runs
Summary
'3cpio -t /boot/initrd.img' ran
2.72 ± 0.03 times faster than 'lsinitramfs /boot/initrd.img-6.1.0-21-amd64'
| Command |
Mean [ms] |
Min [ms] |
Max [ms] |
Relative |
3cpio -t /boot/initrd.img |
210.0 ± 2.3 |
207.1 |
214.7 |
1.00 |
lsinitramfs /boot/initrd.img-6.1.0-21-amd64 |
571.8 ± 1.9 |
568.7 |
574.5 |
2.72 ± 0.03 |