Quote Originally Posted by Joel Eade View Post
I used some very inexpensive 64gb Sandisk SDII cards in the R5 at Laguna Seca and had no issues running into the buffer.
I had previously mothballed my UHS-I cards. After talking with you, watching you do this and looking at my own usage, they are back in circulation.

For my usage, UHS-I is fine, largely because the R5 has a surprisingly good sized buffer. Going with Bryan's data, you are still looking at 151 shots at 12 fps to UHS-I SD card. On the 5DIV, Bryan got 21-36 shots at 7 FPS. Huge improvement. I tend to shoot action shots 1-3 second bursts, which means, I could do ~5 x 30 frame bursts before the buffer filled while the R5 vs ~1 on the 5DIV. After that, it is a matter of how long to clear the buffer.

However, I bought the UHS-II and CFexpress cards. I am primarily using those, but the UHS-I cards in occasional use too and I have yet to have an issue. In the future, I'll probably still pick up CFexpress/UHS-II cards. Just nice to have faster transfer speeds and not having to worry about in camera limitations for when I finally see Big Foot in the woods.