Hi!
Today I did some more tests (already posted the result on "the other" forum
) with a comparison of a 300MB/s UHS II card and a 170MB/s UHS I card. Both tested in both slots. There is not much difference at all. The UHS II card in the UHS II slot has the worst performance though.
The cards are a SanDisk Extreme Pro 170MB/s V30 UHS I card with 128GB.
and a SanDisk Extreme Pro 300MB/s V90 UHS II card with 64GB.
In the PC I get a write speed of 86MB/s and a read speed of 96MB/s in an internal UHS I USB 3 reader for the 170MB/s card. That's pretty much what the interface can handle.
The 300MB/s card does 220-250MB/s writing on the PC (UHS II USB C card reader from SanDisk).
I measured both cards in both slots and get a data rate of around 60MB/s in each of the slots. (a bit less in Slot 2).
The speed of the 170MB/s UHS I card, compared to my 300MB/s card which makes 56MB/s in Slot 1 and 63MB/s in Slot 2 it is almost the same speed at one-sixth of the cost.
Here are my masurements from top to bottom:
170MB/s in Slot 1:
37 Pics for first burst, total of 65 pics during first 15s, 13,6s for clearing buffer, 61MB/s
170MB/s in Slot 2:
36 Pics for first burst, total of 62 pics durinfg first 15s, 12,8s for clearing buffer, 60MB/s
300MB/s UHS II in Slot 1:
36 Pics for first burst, total of 60 pics during first 15s, 13,8s for clearing buffer, 56MB/s
300MB/s UHS II in Slot 2:
36 Pics for first burst, total of 63 pics during first 15s, 11,9s for clearing buffer, 63MB/s
Note that the time for clearing buffer differs slightly due to my reaction time because here I watch the LED with my eyes and then pressed the shutter again.
The camera settings were all the same:
Manual focus, manual mode, 1/8000s, open aperture, ISO 100, lens cap closed (gets all black pictures), DNG only output, SR off, ISO noise reduction off
So I'd say, instead of buying expensive UHS II cards, maybe save your money for the next (Pentax??) camera because I see really no benefit of using UHS II cards.
Btw: The price is
180 € for the 300MB/s V90, 128 GB vs
28 € for the 170MB/s 128GB