A note on variability in speed tests and identifying cards.
Here is the Pi diagnostics on a card:Below is my version of the same test. Some parts are bloated because I dump a file instead of the relevant lines. One thing is noticeable. Every test is slightly different but not enough to change decisions about a card. Perhaps the Raspberry Pi Diagnostics could add the following items.
Here is the Pi diagnostics on a card:
Code:
Raspberry Pi Diagnostics - version 1.4Sun Nov 9 18:06:24 2025Test : SD Card Speed TestRun 1prepare-file;0;0;72656;141seq-write;0;0;71663;17seq-read;89806;21;0;0rand-4k-write;0;0;11720;2930rand-4k-read;23636;5909;0;0Sequential write speed 71663 KB/sec (target 10000) - PASSRandom write speed 2930 IOPS (target 500) - PASSRandom read speed 5909 IOPS (target 1500) - PASSTest PASS- The CPU is identified to allow for tests across different models. Almost anything with Linux.
- The card is identified so there is no confusion when testing several cards.
Code:
sdtest start.Perform a storage speed test on a Raspberry Pi or Linux Mint.SD Card Speed Test from the Raspberry Pi diagnostics program.Plus enhancements.OS from /etc/os-release:PRETTY_NAME="Debian GNU/Linux 13 (trixie)"NAME="Debian GNU/Linux"VERSION_ID="13"VERSION="13 (trixie)"VERSION_CODENAME=trixieDEBIAN_VERSION_FULL=13.1ID=debianHOME_URL="https://www.debian.org/"SUPPORT_URL="https://www.debian.org/support"BUG_REPORT_URL="https://bugs.debian.org/"fio installed.CPU information from /proc/cpuinfo:39:Model: Raspberry Pi 5 Model B Rev 1.037:Revision: d04170Memory usage: total used free shared buff/cache availableMem: 8252416 542256 7017328 40544 809616 7710160Swap: 2097136 0 2097136NVMe:Model: WDC PC SN520 SDAPNUW-512G-1014 Size: 1000215216Firmware revision: 20110000Serial number: 192088453413 microSD:Model: SR64GDate: 12/2021OEM ID: 0x5344Create job file in ./sdtest.tmp.job:Run 1RES: prepare-file;0;0;72979;142seq-write;0;0;72616;17seq-read;91787;22;0;0rand-4k-write;0;0;11643;2910rand-4k-read;23438;5859;0;0Sequential write speed 72616 KB/sec (target 10000) - PASSSequential read speed 91787 KB/sec (target 10000) - PASSRandom write speed 2910 IOPS (A2 target 2000) - PASSRandom read speed 5859 IOPS (A2 target 4000) - PASSRun 2RES: prepare-file;0;0;68985;134seq-write;0;0;73635;17seq-read;92044;22;0;0rand-4k-write;0;0;11815;2953rand-4k-read;24393;6098;0;0Sequential write speed 73635 KB/sec (target 10000) - PASSSequential read speed 92044 KB/sec (target 10000) - PASSRandom write speed 2953 IOPS (A2 target 2000) - PASSRandom read speed 6098 IOPS (A2 target 4000) - PASSRun 3RES: prepare-file;0;0;69149;135seq-write;0;0;73000;17seq-read;92109;22;0;0rand-4k-write;0;0;11594;2898rand-4k-read;24659;6164;0;0Sequential write speed 73000 KB/sec (target 10000) - PASSSequential read speed 92109 KB/sec (target 10000) - PASSRandom write speed 2898 IOPS (A2 target 2000) - PASSRandom read speed 6164 IOPS (A2 target 4000) - PASSList disk space.df -hT -x tmpfs -x efivarfsFilesystem Type Size Used Avail Use% Mounted onudev devtmpfs 3.9G 0 3.9G 0% /dev/dev/mmcblk0p2 ext4 58G 8.1G 48G 15% //dev/mmcblk0p1 vfat 510M 78M 433M 16% /boot/firmwaresdtest end. Used 96 seconds.Statistics: Posted by peterlite — Mon Nov 10, 2025 3:26 am