sudo -s
sysctl -w net.inet.tcp.recvspace=65536`
# give net.inet.tcp.recvspace: 131072 -> 65536
sysctl -w net.inet.tcp.sendspace=65536
# give net.inet.tcp.sendspace: 131072 -> 65536
sysctl -w net.inet.tcp.delayed_ack=0
# give net.inet.tcp.delayed_ack: 3 -> 0

# (-w fichier = True if the file exists and is writable. # explanations from http://manpagesfr.free.fr/man/man1/bash.1.html)

# In the hope of increasing networking performance, I’ve set the following sysctls in /etc/sysctl.conf;

# Increase send/receive buffer maximums from 256KB to 16MB.
# FreeBSD 7.x and later will auto-tune the size, but only up to the max.
net.inet.tcp.sendbuf_max=16777216
# didn't work even with sysctl -w 
net.inet.tcp.recvbuf_max=16777216
# didn't work even with sysctl -w 

# Double send/receive TCP datagram memory allocation.  This defines the
# amount of memory taken up by default *per socket*.
# net.inet.tcp.sendspace=65536
# Already done higher
sysctl -w net.inet.tcp.recvspace=131072
# Give net.inet.tcp.recvspace: 65536 -> 131072

# Enlarge buffers for BPF device.
# sysctl net.bpf.bufsize=65536
# Already done higher
sysctl net.bpf.maxbufsize=524288
# didn't work

# In order to view your photos and other files faster when using the preview, paste this one and restart your mac.
defaults write -g QLPanelAnimationDuration -float 0

# To find the default behavior :
defaults delete -g QLPanelAnimationDuration

defaults write com.apple.finder DisableAllAnimations -bool true; killall Finder
# By relaunching the finder, the files and appear faster.

# To find the default behavior :
defaults write com.apple.finder DisableAllAnimations -bool true; killall Finder

# In a Terminal window, copy the following command to speed up the loading of web pages.
# from https://www.reddit.com/r/apple/comments/4jvx69/some_osx_speed_up_tricks/
defaults write com.apple.Safari WebKitInitialTimedLayoutDelay 0.25

defaults write com.apple.Safari WebKitResourceTimedLayoutDelay 0.0001

# Disable DNS preloading to speed up pages with the following line of code :
# from https://www.cadeboite.fr/mac/mac-safari-5-lent-comment-accelerer-safari/
defaults write com.apple.safari WebKitDNSPrefetchingEnabled -boolean false