Camnostic tested CFexpress cards in the Canon EOS R3 and with the same criteria used in EOS R5 tests. Below is a chart of the megabytes per 30 seconds throughput for those two cameras across a range of popular, high-end cards.
The red bar indicates the R5; the black bar represents the R3 performance (scale at the bottom of the graph), and the green semi-transparent bar shows the card’s retail cost per gigabyte (scale along the top of the graph).
On the R3, the fastest card proved to be the Angelbird XT. Transcend was noticeably slower than the others, but showed the most improved performance relative to its R5 performance. Most cards showed a 2-6 percent throughput increase from the R5 to the R3 camera. On an images taken in 30 seconds measure, of course the R3 did much better – almost twice as well – because the R3’s relatively low resolution sensor produces files that have about half the information in them versus those of the R5.