The Difference between Type I & Type II CompactFlash Cards

Many digital cameras store images on CompactFlash cards.

CompactFlash storage cards, a form of removable memory for digital cameras and other electronic devices, were introduced in 1994. The cards are produced as Type I or the slightly thicker Type II. The vast majority of cards are Type I.

Dimensions

All CompactFlash, or CF, cards measure 1.7 inches long by 1.4 inches wide. CF Type I cards are 0.13 inches thick, while CF Type II cards are 0.19 inches thick. This is the only difference between the two types, but it is significant because while a Type I card will fit a Type I or Type II slot, Type II cards fit only in a Type II slot.

Performance

Speed is a key factor in considering CompactFlash cards. A 1x rating equals a data transfer speed of 150 kilobits per second. Cards typically have a rating of 133x or more, with 600x the fastest available as of 2010. Whether the card is Type I or Type II has no effect on performance, according to the Tom's Hardware website.

Capacity

CompactFlash cards hold up to 64 GB as of 2010. Generally, 16 GB or smaller cards offer the best performance, an important consideration when shooting photos in high-speed bursts or capturing high-definition video.

References

• Tom's Hardware: Roundup: CompactFlash Cards For Professionals: CompactFlash Basics
• Tom's Hardware: Memory Cards, Part 1: CompactFlash From 8GB To 64GB
• CompactFlash Association: Frequently Asked Questions: What is CompactFlash, CF Type I, CF Type II and CF I/O?