Raspberry Pi 1, 2 or 3 and Zero W - microSD Card Speed

From: Raspberrypi.org Forum
https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=144493
https://www.raspberrypi.org/forums/viewtopic.php?f=29&t=188592


Recommended: Sandisk Ultra!!! 32Gb, 64Gb or 128Gb


-Test with a benchmark software (sdbench):

sudo nano sdbench.sh
sudo chmod +x sdbench.sh
sudo ./sdbench.sh


-To fully utilize the speeds for the card, you have to enable sd_overclock in /boot/config.txt:

dtparam=sd_overclock=100

NOTE: It has to be HC-1/UHS-1 or higher (like U1 or higher, or HC-I or higher).


-Run sdbench.sh:
32GB EVO+ Samsung UHS-1/HC-1 micro sdcard in a RPI3

pi@raspberrypi:~ $ sudo ./sdbench.sh

CONFIG:
CLOCK : 100.000 MHz
CORE : 500 MHz, turbo=1
DATA : 512 MB, /root/test.dat

HDPARM:
======
Timing O_DIRECT disk reads: 128 MB in 3.02 seconds = 42.41 MB/sec
Timing O_DIRECT disk reads: 128 MB in 3.05 seconds = 42.03 MB/sec
Timing O_DIRECT disk reads: 122 MB in 3.01 seconds = 40.50 MB/sec

WRITE:
=====
536870912 bytes (537 MB) copied, 27.4302 s, 19.6 MB/s
536870912 bytes (537 MB) copied, 27.386 s, 19.6 MB/s
536870912 bytes (537 MB) copied, 25.623 s, 21.0 MB/s

READ:
====
536870912 bytes (537 MB) copied, 12.312 s, 43.6 MB/s
536870912 bytes (537 MB) copied, 12.3474 s, 43.5 MB/s
536870912 bytes (537 MB) copied, 12.3233 s, 43.6 MB/s

RESULT (AVG):
============
Overlay config core_freq turbo overclock_50 WRITE READ HDPARM
500 1 100.000 MHz 19.12 MB/s 41.54 MB/s 41.63 MB/s


-Turbo mode:

sudo echo 10 > /sys/devices/system/cpu/cpufreq/ondemand/up_threshold
sudo echo 20 > /sys/devices/system/cpu/cpufreq/ondemand/sampling_down_factor