jboner

Latency Comparison Numbers (~2012)
----------------------------------
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

keturn

#!/bin/bash
#
# Add latency to all outgoing traffic on $DEV on tcp/udp $PORT,
# in the amount of $DELAY.
#
# This is matching on both source port and destination port, which
# may hit you twice if you're accessing a local resource.
#
# To see what's currently in effect,
#   tc -s qdisc show dev lo