according to the datasheet https://dl.khadas.com/Hardware/VIM3/Datasheet/A311D_Quick_Reference_Manual_01_Wesion.pdf
The sdcard reader is capable of sdr-104 / UHS-I mode:
- SDSC/SDHC/SDXC card and SDIO interface with 1-bit and 4-bit data bus width supporting specversion 2.x/3.x/4.x DS/HS modes up to UHS-I SDR104
But actually it is only running in high speed mode, not ultra speed mode (at least in coreelec):
sd: new high speed SDXC card at address 0007
clock: 50000000 Hz actual clock: 50000000 Hz vdd: 21 (3.3 ~ 3.4 V) bus mode: 2 (push-pull) chip select: 0 (don't care) power mode: 2 (on) bus width: 2 (4 bits) timing spec: 2 (sd high-speed) signal voltage: 0 (3.30 V) driver type: 0 (driver type B)
This leads to only a write/read speed of about 20MB/s also for UHS-I capable sdcards.
Would it be possible, to support sdr-104 / UHS-I mode in coreelec?