onemach
embolalia
/ gist:5660363
Last active
December 17, 2015 19:29
A quick script that makes my raspi light up for different ping times. It's a terrible hack, and was not written with the intent of making it public. Please don't hurt me.
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| #!/usr/bin/env python | |
| import RPi.GPIO as gpio | |
| from time import sleep | |
| import re | |
| import sys | |
| gpio.setmode(gpio.BCM) | |
| red = 23 | |
| yel = 24 |
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| 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 |