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@jboner
jboner / latency.txt
Last active November 17, 2024 11:32
Latency Numbers Every Programmer Should Know
Latency Comparison Numbers (~2012)
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L1 cache reference 0.5 ns
Branch mispredict 5 ns
L2 cache reference 7 ns 14x L1 cache
Mutex lock/unlock 25 ns
Main memory reference 100 ns 20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy 3,000 ns 3 us
Send 1K bytes over 1 Gbps network 10,000 ns 10 us
Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD
@voltechs
voltechs / no_automount
Last active November 18, 2022 01:29
Add volume (UUID) to fstab to prevent automount (macOS)
#!/usr/bin/env ruby
# Usage: no_automount /Volumes/My\ Disk
diskinfo = `diskutil info '#{ARGV[0]}'`.gsub("\n\n", "\n").split("\n").collect { |b|
b.strip.split(/:\s+/)
}.to_h
disk_uuid = diskinfo['Volume UUID']
disk_type = diskinfo['Type (Bundle)']
@Fobxx
Fobxx / shige-skins.md
Last active November 15, 2024 08:46
Shigetora skins