This text simply compares several SDCards I own regarding speed. I use the cool tool “gnome-disks” to do the testing.
In following image, a defect (?) SD card, that was used in a Raspberry as (only) disk. ON that Raspberry, a (seldom used) Kubernetes cluster was running.
Card is a Sandisk Ultra 32GB , class 10, A1.
Upper card: the broken Sandisk card, lower card, the Samsung, low write speed, but still considered ok
While medium read speed is ok (41,7 MB/s), medium write speed is with 1.7 MB/s very bad.
Maybe the SDCard went bad due to heavy use by the Kubernetes cluster. Another card of same type, running as second node in same Kubernetes cluster, is still fine.
Next card shows a SD Card of same type, which has no issues. Read speed is 72,4 MB/s and write speed is 16,4 MB/s. Card is again a Sandisk Ultra 32GB , class 10, A1.
Next card is a Samsung Evo+ 128GB card. It offers a stable 76.8 MB/s read speed and a 3.6 MB/s write speed. Write speed is slow, but I would say still ok. This card was used for about two years.
Next card is a fresh Samsung 32GB UHS-1 card. It offers a very stable 93.4 MB/s read and 27.5 MB/s write speed. This is the fastest card I have ever owned. I will repeat the speed test in about one year to compare. Card is used in a Kubernetes cluster (master) node as single disk.
The fast, fresh Samsung EVO UHS-1 card. I already have inserted it into the raspberry and cannot take a photo, so here is only the blister…