CompactFlash is the most popular and oldest (was first introduced in 1994) memory card type. Cameras from Canon, Casio, Epson, HP, Kodak, LG, Minolta, NEC, Nikon, Panasonic, Phillips, Polaroid and others use this kind of memory card.

Figure 1: CompactFlash (CF) card.

CF cards can be found in several speed options. A "1x" CompactFlash card transfers data at 150 KB/s. Thus, the data transfer rate of a 16x card is 2.4 MB/s (150 KB/s x 16 = 2,400 KB/s). The only problem is that manufacturers don't say if this transfer rate is for reading or writing. Since read transfer rate is higher than write transfer rate, we think these numbers refer to the read transfer rate.

For the professional market, there are CompactFlash cards with Write Acceleration Technology (WA) tecnology, which provides an extra performance at the same speed grade. For example, a 80x Compact Flash with this tecnology can be up to 23% faster than standard 80x cards. To use this technology, however, your camera must support it. So far only professional cameras from Kodak (all professional models), Nikon (D1x, D1h, D2h and D-100), Pentax (*ist D), Olympus (E1), Sanyo (DSC-MZ3) and Sigma (SD-9 and SD-10) support this kind of memory card. If you install a WA-enabled CompactFlash on a regular camera it will work as a regular CompactFlash card.

Besides the speed advantage, another biggest advantages of the CF cards is that this format is so far the only one that have capacities over 1 GB. You can find CF cards up to 8 GB!

You can find CompactFlash cards in two sizes, Type I and Type II. The only difference between them is the card thickness. CF Type I cards can be installed in both Type I and Type II CF slots, while Type II CF cards only fit Type II slots.

It is very interesting to observe that CF interface is based on PCMCIA (PC Card), but using 50 pins instead of 68. So you can install a CF card directly into a PCMCIA slot on you laptop using a very simple pin adapter. Because of that you can find on the market cards called CF I/O, that are modems, network adapters and other peripherals that use the CompactFlash size, to be installed on laptops or other devices.

Main specs

• Available Capacities: 64 MB, 128 MB, 256 MB, 512 MB, 1 GB, 2 GB, 4 GB and 8 GB
• Transfer Rate: 1x = 150 KB/s, 4x = 600 KB/s, 12x = 1.8 MB/s, 16x = 2.4 MB/s, 32x = 4.8 MB/s, 40x = 6.0 MB/s, 80x = 12 MB/s
• Voltage: 3.3V or 5V
• Power consumption at High Performance: 65 mA at 5V or 50 mA at 3.3V
• Length: 1.43 in (36.4 mm)
• Width: 1.68 in (42.8 mm)
• Height (Type I): 0.13 in (3.3 mm)
• Height (Type II): 0.19 in (5.5 mm)
• Shock: 50Gs @ 11ms
• Vibration: 15 Gs peak to peak
• Operating temperature: 0º C to 60º C (32º F to 140º F)
• Non-operating temperature: -20º C to 85º C (-4º F to 185º F)
• Humidity: 5% to 96%
• For more information: http://www.compactflash.org