Useful Information: Card Classification


SDHC and Classes


      OltraMax SDHC (SD High-Capacity) – is a new generation of SD cards (version 2.0) which will fully satisfy your expectations in terms of reliability, longevity, and durability. Now you can enjoy highly reliable digital world and store any of your files (MP3 music, photos, video) in high resolution using OltraMax SDHC.


      New FAT32 format will also enable you to store files exceeding 4 GB. The new format has introduced a new generation of more powerful SD cards, whereas the old format of SD 1.0/1.1 had storage capacity limitations. A new classification system has its supporting markings and data transmission speed is based on the device class – 2, 4, 6, and 10.

You can find more detailed technical features of these cards in the table below:


  Minimal data transmission speed; Minimal working frequency Minimal data storage block
Class 2 2MB/sec 20MHz 16 KB
Class 4 4MB/sec 20MHz 16 KB
Class 6 6MB/sec 40MHz 16 KB
Class 10 10MB/sec 40MHz 16 KB



More detailed technical features of the cards are provided below:


SDHC Support. New Photo Cameras

Most commercially available digital cameras, including DSLR devices have started using SDHC flash memory cards. It is clear that high definition and high resolution images require larger memory and faster data transmission capabilities. While recording in the RAW format, one data file can be as big as 10 MB - 20 MB, and old cards with 1-2 GB memory space get filled up very quickly. At the same time, SDHC 4 GB - 32 GB is an ideal solution for today’s need for high recording resolution