64GB QUMOX 50MB/s Class 10 UHS-I SDXC SD
It’s your typical Chinese card, you get it easily on ebay, there are also some sellers from within the EU, and it cost you ~27 Euro.
System boots nicely after cloning it.
sync; time dd if=/dev/zero of=~/test.tmp bs=500K count=512; time sync
262144000 bytes (262 MB) copied, 28.0815s, 9.3 MB/s
dd if=~/test.tmp of=/dev/null bs=500K count=1024
262144000 bytes (262 MB) copied, 14.3629s, 18.2 MB/s
So yeah, not exactly 50MB/s at least not on the Pi and prolly never :D
But it’s reasonable fast, big and works. (thus far)
.
.