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Memory Cards for A7Rii


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I have pre-ordered my Sony A7Rii and have been wondering about memory cards. I found a Lexar Professional 1000x 128 gig 150MB/s SDXC UHS-II/U3 card for $57 USD. this seems like a good deal and it said it is backwards compatible to UHS-I devices. Anyone have any advice on if this will be compatible with the A7Rii? I looked on the Sony web site and it looks like it can take a SDXC UHS-I. Since the 4K is 100MB/s I figure this should work well.

 

Does anyone have any preference?

 

Should I not get a UHS-II/U3 version?

 

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I have pre-ordered my Sony A7Rii and have been wondering about memory cards. I found a Lexar Professional 1000x 128 gig 150MB/s SDXC UHS-II/U3 card for $57 USD. this seems like a good deal and it said it is backwards compatible to UHS-I devices. Anyone have any advice on if this will be compatible with the A7Rii? I looked on the Sony web site and it looks like it can take a SDXC UHS-I. Since the 4K is 100MB/s I figure this should work well.

 

 

Careful with the units. The card it is 150 MegaBytes per second (MB/s), the camera records at 4k with 100 MegaBits per second (Mb/s or Mbps). 1 Byte equals to 8 bits... So you will need a card able to keep up around 13MB/s of continuously writing. Usually it is best to get even higher than that, because manufacturers overstate a bit their writting speeds... 

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Hi Gents

 

Thanks to davidgp for the clarification on the Mbit/s vs. MB/s differentiation. That's overlooked  many times.

 

Regarding card speeds you need to differentiate two type indicators - the UHS classification and the minimum write speed classification.

 

UHS is indicated as either UHS-I or UHS-II. The difference here is the bus spped of the card, UHS-I is limited to 104 MB/s, UHS-II to 312 MB/s. That sounds much in the first place, but considering that the bus speed is the limiting factor on writing from camera buffer to memory card one can imagine, that card bus speed is important to stills shooters requiring as much serial speed as possible.

Second is the min write speed. That is indicated by the U1 or U3 labelling on the card. Quite easy to understand, the number is the multiplier to 10 MB/s, meaning U1 cards need to guarantee min writing of 10 MB/s, U3 cards 30 MB/s.

 

Most important is to know whether your camera will support UHS-II.  Because if not, it makes not really sense to pay the additional price tag on the SD card.

Unfortunately the manufacturers do not clearly indicate that even not in the detailed specs.

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