I've been experiencing some issues with my GoPro 11 freezing while recording, and I've been told it might be related to the speed of the SD cards I'm using. I tested a few cards bought on Amazon and found that their read/write speeds were only around 70 to 80 MB/s, while they were advertised to be 200 MB/s for read and 130 MB/s for write. I'm using a Samsung SD adapter with my 2021 M1 Pro MacBook Pro, and I've also tried a USBC adapter from Anker that claims to support 5GB transfer speeds. People are suggesting I might have ended up with fake cards, so I checked one at Best Buy, but the speeds were the same. I have a few specific questions: Is it typical to see speeds that low compared to what's advertised? What's the best software for benchmark testing on a Mac? How long should I run Black Magic's Disk Speed Test? And if the speeds stay low, how can I tell if I've got a counterfeit card?
1 Answer
In your MacBook Pro, UHS-I cards generally cap at around 90 MB/s, while UHS-II cards can reach up to about 250 MB/s. For your GoPro HERO11, which has a maximum bitrate of 120 Mbps, a card only needs about 15 MB/s write speed in real-world usage. GoPro recommends U3 cards that are rated for a minimum of 30 MB/s. Just make sure you’re clear on the difference between Mbps and MB/s, as they represent different units of measurement.
Ahhh ok that makes sense. Thank you!