Performance

Table of contents

• Statistics
  • Memory usage
  • Disk usage
    • Binary size
    • Package size
• Performance
  • System calls
  • Listing time
• Optimization
  • Getting some extra performance
  • Clifm and terminal emulators

1) Statistics

All the following tests were executed on exactly the same system using clifm 1.14.

a) Memory usage

Data retrieved via htop

Application	Resident (3,549 files)	Resident (100,000 files)
ranger	43384k	542M
rnr	71828k	--fails--
lf	22608k	103M
xplr	13484k	149M
yazi	14504K	45M
mc	12204k	35M
broot	11960k	--fails--
vifm	9816k	101M
clex	7368k	78M
joshuto	7512k	38M
fff	6366k	79M
clifm	6252k	24M
nnn	4040k	10M
cfiles	3796k	--fails--

b) Disk usage

Data retrieved via: du

b.1) Binary size

Binary	Size
/usr/bin/broot	10316k
/usr/bin/yazi	8176K
/usr/bin/xplr	5044k
/usr/bin/joshuto	4420k
/usr/bin/lf	3864k
/usr/bin/vifm	1560k
/usr/bin/mc	1260k
/usr/bin/clifm	920k1
/usr/bin/pilot	736k
/usr/bin/clex	420k
/usr/bin/nnn	120k
/usr/bin/cfiles	44k

¹ If compressed via upx(1) we get a much smaller binary size: 404k.

b.2) Package size

Data retrieved via pacman -Qi

Package	Installed size
broot	10.71 MiB
yazi	7.99 MiB
mc	7.03 MiB
joshuto	4.68MiB
lf	4.30 MiB
xplr	5.21MiB
vifm	2.84 MiB
ranger	2.64 MiB
clifm	1.30 MiB
clex	439.20 KiB
rnr	633.29 KiB
nnn	346.41 KiB
cfiles	45.43 KiB
fff	45.39 KiB

c) Performance

c.1) SysCalls (listing 3,549 files)

Data retrieved using strace -c

Application	Syscalls
cfiles	113,079
joshuto	90,592
lsd	65,607
xplr	30,955
rnr	15,782
fff	11,895
ranger	10,461
clifm	9,7131
mc	9,194
clex	8,403
exa	5,645
broot	5,088
nnn	3,786
clifm (light)	1,508
ls	964
lf	322

¹ A third of these syscalls are used to check files for capabilities. If you don't need this check, you can run with --no-file-cap (note that on non-Linux systems this check is never performed).

c.2) Listing time: clifm vs ls(1) (listing 100,000 files)

Note that the clifm commands below attempt to replicate the corresponding ls output, focusing only on listing speed (which is why we disable some clifm-specific features: config files (-S), external commands (-x), ELN's (-e), file capabilities and extension checks (--no-file-cap, --no-file-ext), and names trimming (--no-trim-names)).

These tests have been performed using time(1) with the -p option.

a. Normal mode

clifm -Sxe --list-and-quit --no-file-cap --no-file-ext --no-trim-names:

real 0.94
user 0.26
sys 0.31

ls --color=always:

real 0.93
user 0.36
sys 0.34

b. Long/detail mode

clifm -LSxe --list-and-quit --no-file-cap --no-file-ext --no-trim-names --no-color:

real 1.98
user 0.73
sys 0.75

ls -l:

real 2.02
user 0.67
sys 0.83

---

As you can see, clifm performs quite well on each of the testing fields, positioning itself overall among the most performant terminal file managers for Unix systems.

2) Optimization

Getting some extra performance

As you can see, clifm is by itself quite fast by default. But if speed is still an issue, it is possible to get some extra performance:

1. Disable the files counter, used to print the amount of files contained by listed directories. Disabling this option produces a nice performance boost.¹

2. Disable some features: icons (if enabled), columns, sorted files, directories first, files capabilities check, files extension check, symlinks resolution, Unicode, colors, and, if already running without colors, file type indicators (classification):

clifm --no-colors --no-columns --no-classify --no-files-counter --no-unicode --no-dirs-first --sort=0 --no-file-cap --no-file-ext --no-follow-symlink

3. Run in light mode

4. Limit listed files. Because listing lots of files could be expensive and time consuming, you can also try to limit the amount of files printed for each visited directory (see the mf command).

5. Run in stealth mode

6. Compile in/out a few features:

a) Compile with `-D_TOURBIN_QSORT` to use Alexey Tourbin faster qsort implementation instead of **qsort(3)**. \
b) Compile out features you don't need to get a bit smaller, and thereby faster, executable. For example, to compile out icons and translation support:

clang ... -D_TOURBIN_QSORT -D_NO_GETTEXT -D_NO_ICONS ...

For more information consult the compiling features in/out section.

¹ Disable the files counter either via the --no-files-counter command line option, the FilesCounter option in the configuration file or the fc command.

Clifm and terminal emulators

Despite the above, however, it is important to bear in mind that listing speed does not only depend on the program's code and enabled features, but also on the terminal's rendering speed.¹ Old, basic terminal emulators like Xterm, Aterm, and the kernel built-in console are quite slow compared to more modern ones like Urxvt, Lxterminal, ST, or Alacritty, to name just a few.²

¹ On this topic, see this excellent article written by Anarcat. See also https://stackoverflow.com/questions/3857052/why-is-printing-to-stdout-so-slow-can-it-be-sped-up.

² If using Xterm, setting the fastScroll resource to true in your ~/.Xresources file produces a quite decent performance boost in terms of rendering speed: XTerm*fastScroll: true. Even thus, nonetheless, it is far behind modern terminal emulators, specially when it comes to large directories.