SDHC cards are featured in four performance classes:
SD2 = Class 2 (2 MB/sec minimum data transfer rate)
SD4 = Class 4 (4 MB/sec minimum data transfer rate)
SD6 = Class 6 (6 MB/sec minimum data transfer rate)
SD10=Class 10 (10 MB/sec minimum data transfer rate)
Card Formats:
SD = up to 2GB
SDHC = 4GB to 32GB
SDXC = above 32GB to 2TB
Bank Schema
SD/SDHC/SDXC:
Config / Kingston Part Number / Qty (Upgrade Path)