I did not say that SD cards in the R5 is incapable of handling 45MB files. Of course they are.
What I was saying that in MY use case, the shooting I do will saturate the buffer and hit a limit with any SD cards write speed. Even the 5D4's buffer I would saturate quickly. Add 45MB RAW shots and that makes What I shoot is almost as speed-necessary as a sports photographer and as our shoots are quite expensive and with that kind of money involved, I might lose that moment.
I don't get why my original statement triggers you. My use case is not yours. If your style of shooting does not stall the camera, well then hats off to you. You get a gold star. Not everyone is like you. For others, it's a legitimate concern and frankly, does not need explaining. I'm not discounting the R5 before it's even out of the gate. I'll see what real-world performance does with that kind of setup. Obviously it will work for a majority of users. Great. I'm not a "majority".
No mirrorless camera to-date have impressed me enough to move off my 5D3. I almost bought a 5D4 but then decided to hold off as rumors of a 5D mirrorless-equivalent started to circulate.
++++++ I did not say that SD cards in the R5 is incapable of handling 45MB files. Of course they are.
really? this is exactly what you said:
"... The 5DM3 is a 22MP camera.
If the R5 rumor points to a 45MP camera, then those SD cards (even the latest) will not be fast enough to handle that kind of bandwidth ..."
The use case you described is way above what 5D3 is capable of supporting of. I am not even sure why you bother holding to a 5D series camera body if your use case is what you described. Even writing to a single CF card will get you no more that 11 shots until 5D3 buffer will reach full capacity. 5D4 is a bit better in that regard but still its not a sport camera like a
1D series rig.
To be correct, I objected your position that : because if SD card is slow in your 5D3, it won’t be up to task in R5 either.
SD tech in 5D4 and R5 is A completely different tech to the one in your 5D3. 8 times faster.
Shooting with 5D3 a fast action with long bursts that saturate buffet really quickly and on expensive shoots sounds mega awkward to me. You rig is just not up to speed even with a single CF card in there. Let alone writing to two cards simultaneously.
I shoot with a pair of 5D4 bodies continuously when required but in short bursts of no more that 8-10 shots at a time. That’s about a second and a half worth of action.
However, 5D4 allows up to 2.5 seconds of continuous high speed shooting to both cards before you reach buffer saturation. That’s from experience.
So .. your understanding of UHS - II capabilities in Canon modern cameras is a little bit misaligned.