Storage [Q] MicroSD class difference? On our Pico

Sorry for spam. I know there is many thread for same question i want to hear something from pico users

i hope i ll buy a new sd soon... and its maybe sandisk ult microsd class 10. 16gig

But i don t know is class 10 can slighly improve performance ? (making 3 partitions for roms or OCing)

now i have 8 gig class 4... 3 partition requed roms and int2ext ..etc works slowly... what is the reason for the slow? is it sd card problem?

thanks for your effort... and some google translate....