Any affordable-speed-quality.
Unlike GPD WIN 1, the WIN 2 card reader has no visible limitations.
Cards tested by users
reddit:
Figures: Sequential Read, Sequential Write, 4K Random Read, 4K Random Write in MB / s
16 GB Lexar 633x ** - 88, 25, 8.7, 1.2
Panasonic U3 ** - 93, 42, 11, 0.7
Sandisk Extreme Pro - 95, 80, 7.6, 2.6
32 GB Delkin U3 - 93, 59, 11, 0.6
Kingston 90R / 80W - 93, 58, 11, 0.6
Lexar 1000x - 90, 57, 10, 1.4
Lexar 1000x with Bundled Reader * - 148, 60, 10, 1.4
Patriot EP - 90, 35, 10, 0.6
PNY Turbo Performance - 91, 55, 6.9, 0.9
PNY Elite Performance Lime Green - 94, 55, 7.4, 1.0
Samsung Pro gray - 92, 82, 10, 3.6
Sandisk Extreme Pro - 94, 87, 9, 3.0
Sony up to 95MB / s - 91, 51, 4.8, 0.9
Transcend Ultimate 633x - 93, 85, 8.1, 1.4
64 GB Delkin U3 - 94, 27, 13, 0.3
Kingston 90R / 80W - 94, 25, 13, 0.3
Lexar 1000x - 92, 56, 12, 1.5
Lexar 1000x with Bundled Reader * - 153, 66, 11, 1.7
Patriot EP - 81, 22, 11, 0.6
PNY Turbo Performance - 92, 54, 6.9, 0.9
PNY Elite Performance Lime Green - 92, 54, 7.5, 1.0
Samsung black - 82, 20, 8.8, 2.1
Samsung Pro gray - 90, 80, 10, 3.5
Samsung Pro + *** - 92, 86, 10, 5.3
Sandisk Extreme U3 - 92, 88, 5.5, 0.5
Sandisk Extreme Plus U1 **** - 92, 58, 10, 2.8
Sandisk Extreme Plus U3 - 92, 88, 9.4, 2.9
Sandisk Extreme Pro - 97, 91, 10, 3.0
Sandisk Ultra ***** - 46, 16, 7.0, 2.1
Sony up to 95MB / s - 92, 49, 5.2, 0.9
Transcend Ultimate 633x - 93, 83, 7.3, 1.4
128 GB Lexar 633x - 78, 28, 3.3, 1.4
PNY High Performance - 81, 22, 5.4, 0.9
Samsung EVO + - 82, 26, 5.9, 1.2<== the listed product
Sandisk Ultra - 92, 19, 6.4, 2.4