Which SD card to use in the Canon R7?

The Canon R7 has two UHS-II slots and relatively limited buffering capacity.  To delay hitting the buffer limits, the ‘no-expense spared’ solution would be to buy expensive well reviewed UHS-II SD cards such as the Lexar Professional 2000x (£154 for 128Gb), ProGrade Digital SDXC UHS-II V90 300R (£149 for 128Gb) or the Sony SF-G series TOUGH (£189 for 128Gb).  Or perhaps the even more expensive 256Gb versions. However, some of us can’t afford these high-end solutions – hence the rest of this post.

The similarly specified but more modestly priced Kingston Canvas React Plus SD card has also been well reviewed on several camera sites, so I purchased this when the price dropped, briefly, on Amazon UK to £83 for the 128Gb card.  I also managed to pick up two Kingston Canvas React Plus 64Gb micro-SD cards for the ridiculously low price of £12 each from another UK site. These don’t seem to be available anymore – I think they may have realized their pricing error!

Using Crystal Disk Mark v7,  I tested these cards together with a range of memory cards we had in our house. I had no idea how this relates to in-camera use but at least it was objective data.  The results for one subset of testing are given below.

My take on these results was that the Kingston Canvas React Plus 128Gb SD card was to be my primary card for camera use, closely followed by the microSD card version.

However, I tried the Kingston SD card UHS-II and a lowly UHS-I card in my camera (then an Olympus EM1 MkII) using a mechanical shutter noise test, to time when the buffer was hit.  There was a difference but not to the extent visualised in the data i.e., the real-world situation was not so clear cut.

With my recent purchase of the Canon R7, I tried to devise a simple objective test that was a better fit to the real-world situation   This second set of data is time taken to transfer 200 cRAW files (about 4.2Gb) from a fast NVME drive to the memory cards.  The cards were all in the same UHS-II reader and the times were averages of three runs.

Surprisingly the well regarded  Kingston SD card 128Gb UHS-II exhibited huge variations in transfer speeds during the runs, which significantly slowed it down.

Conclusion (and congratulations if you made it this far)   

1. I’m going to use the Kingston Canvas React Plus UHS-II 64Gb microSD card and Transcend 64Gb UHS-II SD card in the Canon R7.  
2. The Kingston Canvas Select Plus UHS-I card looks like an excellent value cheap card to have lying around for emergencies.