Se instala fácilmente desde los repositorios.
sudo apt-get install conky
Luego debes crear un archivo de configuración en tu directorio personal, debe llamarse “.conkyrc”. Las configuraciones para este archivo las puedes encontrar en la sección de screenshots del sitio de Conky.

Yo personalmente uso esta configuración:

# maintain spacing between certain elements
# Update interval in seconds
update_interval 2
 
 # Create own window instead of using desktop (required in nautilus)
own_window yes
own_window_transparent yes
own_window_type override
 
# Use double buffering (reduces flicker, may not work for everyone)
double_buffer yes
 
# Minimum size of text area
minimum_size 150 5
 
#send to background
background yes
 
# Draw shades?
draw_shades yes
 
# Draw outlines?
draw_outline no # amplifies text
 
# Draw borders around text
draw_borders no
 
# Stippled borders?
stippled_borders 0
 
# border margins
border_margin 1
 
# border width
border_width 1
 
# Default colors and also border colors, grey90 == #e5e5e5
default_color grey90
default_shade_color black
default_outline_color DarkGrey
 
# Text alignment, other possible values are commented
#alignment top_left
alignment top_right
#alignment bottom_left
#alignment bottom_right
#747574
 
# Gap between borders of screen and text
gap_x 9
gap_y 60
 
# Subtract file system buffers from used memory?
no_buffers yes
 
# set to yes if you want all text to be in uppercase
uppercase no
 
# stuff after 'TEXT' will be formatted on screen
 
TEXT
${color #ffcb48}${color #ffcb48}  ${nodename} ${machine}
${color #98c2c7}Uptime: ${color white}${uptime}
 
${color #98c2c7}Bateria: ${color white}${battery}
 
${color #98c2c7}Kernel: ${color white}${kernel}
${color #98c2c7}Fecha: ${color white}${time %A,%d %B}
${color #98c2c7}Hora: ${color white}${time %k:%M}${alignr}
 
${color #ffcb48}PROCESANDO$color
${color #98c2c7}CPU:${color } $cpu % ${color #78af78}
Core 1
${cpubar cpu1 4,158}
Core 2
${cpubar cpu2 4,158}
 
${color white}USO DE PROCESADOR
${color #98c2c7}APLICACION         CPU%        
${color #e5e5e5}${top name 1}   ${top cpu 1}    
${color #c4c4c4}${top name 2}   ${top cpu 2}
${color #a3a3a3}${top name 3}   ${top cpu 3}
${color #828282}${top name 4}   ${top cpu 4}
 
${color white}USO DE MEMORIA
${color #98c2c7}APLICACION        RAM%
${color #e5e5e5}${top_mem name 1}   ${top_mem mem 1}
${color #c4c4c4}${top_mem name 2}   ${top_mem mem 2}
${color #a3a3a3}${top_mem name 3}   ${top_mem mem 3}
${color #828282}${top_mem name 4}   ${top_mem mem 4}
 
${color #98c2c7}[RAM]:${color}$memperc% ${color #78af78}$mem/$memmax
${membar 4,158}
${color #98c2c7}[SWAP]:${color}$swapperc% $swap/$swapmax
${swapbar 4,158}
${color #98c2c7}[ROOT]:${color}${color #78af78} ${fs_free /}${color #78af78}/${fs_size /}
${fs_bar 4,158 /}

Si pones Conky como carga automática al inicio de tu sesión, debes ponerle un retardo, para que pueda capturar correctamente el area del escritorio donde se mostrará.

#!/bin/sh
sleep 30
conky