SanDisk 256GB Extreme PRO SDXC card

Yella Fella · 10 Jul 2023 at 17:29

Forgive me if this is the wrong thread for removal storage.

I bought 2x of these cards recently and they are rated at 200MB/s though both had the exact same serial number on them.

I ran some tests, and bought again a new memory card reader, SanDisk Extreme PRO SD UHS-II USB-C Card Reader. However, I'm only getting max speeds of around 90MB/s which sounds a bit sussed.

Do anyone else have these cards? Do you get consistently the same speeds as me or more closer to 200?

Snapshot · 11 Jul 2023 at 08:58

Are you talking about read or write speeds? 200MB/s is the maximum read speed but 90MB/s is the card's rated write speed.

Yella Fella · 11 Jul 2023 at 09:21

Read speeds as they have always been fine on camera.

Snapshot · 11 Jul 2023 at 12:15

My immediate thought was 'fakes' when you said they had the same serial number but I've just checked my five 64GB 170MB/s cards and found three have one number and the other two a second one so I'm less concerned by it.

I've just run one of my cards through H2testw and got 94.8MB/s for write and 143MB/s for read. I then found a Sandisk reader which gave me 155MB/s read.

So with a suitable reader, which yours certainly should be, the card should get close to its rated read speed. Is the port on the PC USB-C or USB-B?

Yella Fella · 11 Jul 2023 at 12:32

That's what I thought. I've tried it on both my Macbook Pro and Windows PC via USB-C. I suspect fake cards, never mind I've returned them now.