jbobfunky
Posts: 23
Joined: Sat Oct 05, 2019 12:19 pm

Raspberry Pi Diagnostics

Thu Dec 03, 2020 10:50 am

Hello and hope all is well and safe!

This morning I noticed a neat little program called Raspberry Pi Diagnostics in the RPi 3. Cool... Apparently it checks the SD card write and read speeds..... and mine FAILED! Huh?

I'm running a Onn 32G SD Card. Yea.. not super name brand but its been working as my main card.

I also have a Samsung 32G Evo Plus clone of Onn SD card. Freshly cloned with the SD Card Copier. Super name brand... that FAILED too!!

Here's what the detail of that diagnostic run...

################################

Raspberry Pi Diagnostics - version 0.5
Thu Dec 3 04:33:51 2020

Test : SD Card Speed Test
Run 1
prepare-file;0;0;9598;18
seq-write;0;0;9465;18
rand-4k-write;0;0;632;158
rand-4k-read;8164;2041;0;0
Sequential write speed 9465 KB/sec (target 10000) - FAIL
Note that sequential write speed declines over time as a card is used - your card may require reformatting
Random write speed 158 IOPS (target 500) - FAIL
Random read speed 2041 IOPS (target 1500) - PASS
Run 2
prepare-file;0;0;9653;18
seq-write;0;0;10505;20
rand-4k-write;0;0;638;159
rand-4k-read;8026;2006;0;0
Sequential write speed 10505 KB/sec (target 10000) - PASS
Random write speed 159 IOPS (target 500) - FAIL
Random read speed 2006 IOPS (target 1500) - PASS
Run 3
prepare-file;0;0;16185;31
seq-write;0;0;14000;27
rand-4k-write;0;0;308;77
rand-4k-read;8547;2136;0;0
Sequential write speed 14000 KB/sec (target 10000) - PASS
Random write speed 77 IOPS (target 500) - FAIL
Random read speed 2136 IOPS (target 1500) - PASS
Test FAIL

##################################################

I was like wow on both cards FAILING the test.

I guess the questions are...

What's the deal with this and what should I do? If something should be done...

And

What are the best SD cards to use for these things?

Thanks in advance!!
~ jbobfunky

User avatar
topguy
Posts: 7189
Joined: Tue Oct 09, 2012 11:46 am
Location: Trondheim, Norway

Re: Raspberry Pi Diagnostics

Thu Dec 03, 2020 11:12 am

Do you have other programs/services running in the background when running these tests ?

There is this other small command line tool called "dstat" that can show system load for CPU/disk/network.

The values it checks against seem to be for Class A1 cards.

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