The Canon EOS R5 will have an SD & CFExpress slot [CR2]

docsmith

EOS R
CR Pro
Sep 17, 2010
1,003
439
why is a UHS-II SD slot suddenly useless?
Useless is an exaggeration. But having a card that can do 1-4 GB/sec and a card that can do ~300 MB/sec (and I think that is read speed) does introduce issues when you are pushing the limits of the camera. For example, 12 fps x 60 MB (assuming) files = 720 MB/sec. With the CFExpress card, you do not need to buffer that. With the UHS II card, you can not write directly to the card, thus it will need to be buffered. So, this is like having a Ferrari tethered to a Honda. Nothing is wrong with the Honda, other than to get the full performance out of the Ferrari you will need to cut the tether. In doing so, now you are shooting to a single card slot. For most applications this is not an issue and the low cost of the SD card and the fact that SD card readers are common is appreciated.

So, what did we just learn? The R5 will have its burst rate limited by buffer capacity if you want to shoot to both card slots. So starts the ways that we will see the R5 limited compared to the 1DX III. And this is not me whining. This was expected, it is a $3k camera compared to a $6,500 camera.
 

richperson

EOS 90D
Sep 6, 2019
174
198
I'm glad they have two different slots. The small slot for JPEG backups is nice. Also nice in those times when you want to record raw on the main card, but JPEG on the small card for ability to hand the card immediately to someone with a reader to print/transfer the file. If you had two CFExpress slots then you would have to bring the bulky reader with you or plug to the camera.
 

richperson

EOS 90D
Sep 6, 2019
174
198
So, what did we just learn? The R5 will have its burst rate limited by buffer capacity if you want to shoot to both card slots. So starts the ways that we will see the R5 limited compared to the 1DX III. And this is not me whining. This was expected, it is a $3k camera compared to a $6,500 camera.
I don't think this is totally accurate. It sounds like you are assuming raw to both cards, which I don't know why you would do that. If you shoot raw to the fast card and JPEG to the small card it shouldn't impact the buffer significantly should it?
 

richperson

EOS 90D
Sep 6, 2019
174
198
Good news for still shooters since CFExpress has no value for stills (for a few of these cards one can better buy an RF lens)
Not true. If you are shooting high burst rate raw, then the faster speed likely will work with the processor to get you more shots in before the buffer is full, no? And, although not a huge deal, it is faster if you shoot 1000 raw files to get them on your computer.

When I run my 7Dii with both cards, if I accidentally set it to the SD slot, the fps lags repeatedly while it tries to write.
 
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Codebunny

EOS R1
Sep 5, 2018
647
631
I'm glad they have two different slots. The small slot for JPEG backups is nice. Also nice in those times when you want to record raw on the main card, but JPEG on the small card for ability to hand the card immediately to someone with a reader to print/transfer the file. If you had two CFExpress slots then you would have to bring the bulky reader with you or plug to the camera.
The second slot could have been a CFExpress type A, which is as small as a SD card
 

Codebunny

EOS R1
Sep 5, 2018
647
631
Supposedly funny? Not everyone shoots videos. SD is sufficientfor stills.
SD is not going to let you pull off 12/20 FPS 40+ MP/s. It's also going to greatly slow down dumping the data onto you computer. I have absolutely no interest in video, or I would buy a C line camera or better.
 
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joestopper

Rrr...
Feb 4, 2020
231
207
Not true. If you are shooting high burst rate raw, then the faster speed likely will work with the processor to get you more shots in before the buffer is full, no? And, although not a huge deal, it is faster if you shoot 1000 raw files to get them on your computer.

When I run my 7Dii with both cards, if I accidentally set it to the SD slot, the fps lags repeatedly while it tries to write.
It will depend on the buffer size and how many burts for sure. Anyway, I am talking more of the regular stills shooter like architecture, landscape, portrait etc. Sports is a different story. But then, well, there is the other slot with CFExpress. Having a fast and a regular makes a lot of sense.
 
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joestopper

Rrr...
Feb 4, 2020
231
207
SD is not going to let you pull off 12/20 FPS 40+ MP/s. It's also going to greatly slow down dumping the data onto you computer. I have absolutely no interest in video, or I would buy a C line camera or better.
I am talking of stills. 12/20 FPS is already a movie...