Why SD card speed claims can be misleading for cameras drones and Raspberry Pi

[Stuart_67]

SD card packaging loves big numbers, but the number on the front is not always the number that matters for your device. Cameras care about sustained write speed, drones care about reliable recording, and Raspberry Pi projects often care about small random reads and writes. The SanDisk 128GB Extreme PRO SDXC Card and SanDisk Extreme PRO 128GB SDXC UHS-I Card are sensible examples of cards people buy because they are known rather than mysterious. If you read cards through a laptop with limited ports, a hub such as the Anker 555 USB-C Hub 8-in-1 can also affect real world transfer speed. My rule is simple: buy for the actual device and workload, not just the biggest speed number in the product image.

[QuantumToken98]

This is exactly why benchmark posts are useful. The advertised numbers do not tell the whole story.

[Drifter]

For cameras I care about sustained writes more than anything. Dropped video is not worth saving a few pounds.

[Quanta]

I have noticed readers make a big difference too. The same card can feel totally different in a better adapter.

[TheLegendBrett88]

For Raspberry Pi use I look at reliability first. Speed is nice, but corruption is the real nightmare.