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Write speed on DSXC card for 6D Mark II


I need to buy a second card for my 6D Mark II and am a little bewildered by all the acronyms and abbreviations. I think I have the SDXC generation of card selected correctly but am wondering about "write speed." The 6D M II ha a shutter burst speed of 6.5 fps. If my math is correct, at 24M per frame, that would mean I would need a card with a write speed of about 150M?




I always used SanDisk Extreme Pros 95mb's, UHS-I, Class 10 ,v30's in my 6D2.  In the 6yrs I owned the body, I only had an issue 1 time with high speed shooting.  I think it was because I didn't format the card in camera before the shoot.  


See Drive System and Max Burst:


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Thanks. I am trying to learn the terminology. Is this an SDXC generation disk? What does Class 10, v.30 mean? 


THIS article explains the differences between the iterations of SD cards.

THIS article talks briefly about the UHS speed class.

I hope this helps! 


You may find THIS article helpful. 

I appreciate the clarifications on terminology but it does not address my question - write speed in relationship to to shutter burst speed 


All cameras have a buffer.
Think of that buffer like a bucket. It holds the photos or videos you take while waiting to be saved to your memory card. Think of those like water going into the bucket. OK?
When you take a single photo, it's just like a single cup of water going into the bucket - you're not in any jeopardy of the bucket getting full. It does its job of holding your photo long enough to transfer to your card.
Now, let's say you start taking multiple photos back-to-back in a burst. Your bucket starts to fill up.
If your card is slow, it won't be able empty the bucket as quickly as the water is going into it, and the bucket will fill up, and the camera will stop allowing you to put more water into the bucket. (Your bottleneck is the card)
If you have a faster card (all cards nowadays are class 10, UHS-I or better, so you're going to be looking at the actual write speed), it will empty the bucket almost as quickly as you're putting water into it, and you won't ever have a bottleneck at the card. 

Obviously, I've broken this down into terms I'd explain it to my grandma so that she could understand it. I sincerely hope I didn't offend you at all. 😊

Well, I didn't realize my posts invited such a simplistic explanation, but my takeaway is that the camera's buffer will simply stage the first round of bursts easily enough to give the card a chance to file them. Thanks.  

Not at all! I couldn't think of a better way to explain this concept. I talk to my grandma almost everyday, so I imagined how I'd explain it to her! 😂

I'm not able to edit a post for some reason, but good practice to never be insulted by someone seeking to help!