How many mins of 4K video can a 32/64 GB SDXC memory card can hold?

Started Apr 15, 2016 | Questions
Markr041 Veteran Member • Posts: 8,215
Here's a more confusing example

Michael Trenton wrote:

nigelht wrote:

http://alikgriffin.com/best-sd-memory-card-sony-a7rii

Here is an interesting blog post on why this might be for Sony. The hypothesis is unproven but interesting.

But if true it might explain Sony's requirements and why it appears some cards are flakey in Sony gear.

That was an interesting read. Strange that Sony would bottleneck the write speeds an expensive camera like the A7RII for what appears (to me at least) to be no apparently good reason.

Still, this may just be me, but even after reading that blog post I'm still confused as to why the RX100 IV refuses me to record 100Mbps 4K onto my PNY 64GB SDXC U-3 by giving me an error message saying the card is not fast enough. Because clearly the camera is capable of writing fast enough to other U-3 cards so it can't be the camera itself, nor the U-3 standard that's the bottleneck right?

Unless PNY is the culprit here and their advertised U-3 card doesn't deliver above 30MB/s sustained write speeds, but rather sub 12,5 MB/s write speeds which would make the card too slow for 100Mbps 4K?

EDIT:

Wait, I think I understand it now. It's because some U-3 memory cards use a protocol not supported by Sony is that it?

My brand new *Sony* 64GB sdxc u3 card was considered not usable by my Sony RX100 IV camera for 4K video!

The same card works fine in 4K at the same 100 Mbps in my Panasonic camera. I have no idea what is going on.

Sandisk 64GB sdxc u3 was ok in the Sony; Samsung 64GB sdxc u3, not OK.

 Markr041's gear list:Markr041's gear list
Panasonic Lumix DMC-FZ200 Panasonic LX100 Sony RX100 IV Panasonic ZS100 Olympus TG-5 +12 more
Michael Trenton Regular Member • Posts: 185
Re: Here's a more confusing example

Markr041 wrote:

My brand new *Sony* 64GB sdxc u3 card was considered not usable by my Sony RX100 IV camera for 4K video!

The same card works fine in 4K at the same 100 Mbps in my Panasonic camera. I have no idea what is going on.

Sandisk 64GB sdxc u3 was ok in the Sony; Samsung 64GB sdxc u3, not OK.

Hmm. This again points to Sony being the culprit and not the card manufacturer. Surely it can't be the card itself when it works just fine for the same bitrate in a different camera?

Maybe the problem is indeed that Sony has skimped out on support for some U-3 write protocols in their cameras which causes problems when memory cards using a different U-3 write protocol than the camera supports is used and the camera is then forced to use a different and slower write protocol (one intended for U-1 perhaps?) in order to use the card. I don't know.

If that's the case then it's an even bigger travesty that Sony's own brand of U-3 memory cards isn't even supported by their own cameras.

 Michael Trenton's gear list:Michael Trenton's gear list
Sony RX100 IV Canon EOS 60D Sony a6300 Canon EF 50mm F1.8 II Canon EF-S 18-55mm f/3.5-5.6 +11 more
Keyboard shortcuts:
FForum MMy threads