The SD card is connected in 4bit / 3.3V SDR25 (25MB/s) mode like on the normal Pine boards, the eMMC is connected in 8bit / 1.8V mode and uses HS-200 (200MB/s) mode.
As with any SBC running normal OS stuff, speed grade of the card is less important than the random I/O performance which is sadly not specified by vendors atm and can well be bad for cards that have high speed grades. Currently most people have good experience with the Samsung 32/64GB EVO(+) cards (see sdcard thread in the beginner forum). The SD-card association has recently released two new 'application' grades for new cards (A1/A2) that try to give an idea of the random I/O performance of cards for applications.
https://forum.pine64.org/showthread.php?...3#pid12693
http://forum.armbian.com/index.php/topic...rformance/
http://www.cnx-software.com/2017/06/13/m...ps-tricks/
As with any SBC running normal OS stuff, speed grade of the card is less important than the random I/O performance which is sadly not specified by vendors atm and can well be bad for cards that have high speed grades. Currently most people have good experience with the Samsung 32/64GB EVO(+) cards (see sdcard thread in the beginner forum). The SD-card association has recently released two new 'application' grades for new cards (A1/A2) that try to give an idea of the random I/O performance of cards for applications.
https://forum.pine64.org/showthread.php?...3#pid12693
http://forum.armbian.com/index.php/topic...rformance/
http://www.cnx-software.com/2017/06/13/m...ps-tricks/
Come have a chat in the Pine IRC channel >>