CFast (for Compact Fast) is a new standard of memory card. It’s designed to store the huge file sizes created by DSLR high megapixel cameras and 4K video cameras.

What is CFast?

The CFast 2.0 specification provides for speeds of up to the SATA 3.0 interface max of 600MBps. Wait! What?

OK. SATA means Serial ATA. ATA is an abbreviation of AT Attachment.  AT was IBM’s acronym for Advanced Technology. Whew. Therefore, SATA is the abbreviation for Serial Advanced Technology Attachment. Ancient Computer History Note: AT comes from the name of the the original IBM Personal Computer AT. The IBM PC AT was the first widely available computer whose hard drive was tied to the machine’s overall performance. SATA replaced the original PATA (the P is for Parallel.) This technology update made for faster speeds, hot swapping and simpler cables–7 wires instead of 40 or 80 in PATA.

MBps is Mega Bytes per second. Don’t confuse MBps with its smaller cousin. Mbps or Mega bits per second.A Byte is 8 bits. Internet speed is measured in Mbps. A download speed of 64Mbps works out to 8 Megabytes of data per second. Bottom line: 600 Megabytes of data transfer every second is wicked fast. At that speed a typical HD 1080p movie would download in two to three seconds! If only.

2923-cfast-card-slots-copyThe CFast card

CFast cards are physically the same size as a Compact Flash card. There are differences in the case that keep CFast from fitting in a CF slot and vice versa. CFast uses two sets of female pins in two slots. 7 pins transfer data while 17 handle power. CFast cards require a dedicated card reader. Currently, prices for readers are in the $45.00 to $100.00 price range.

Cameras need speed

The first camera to use the CFast 2 was Arri’s Amira digital cinema camera. It can shoot 200 frames per second at 4k. A frame of 4K video is 8.3 megapixels. 200 of them every second is a whole lot of data. DSLRs are data hogs too. The Canon 1Dx Mark II can shoot 16 frames of RAW per second for 170 frames. That’s 4.7 gigabytes of photos made in ten and a half seconds. Each frame is 26.5 megabytes. Now, granted, that frame rate isn’t something one might do everyday. It is, though, a trend. The trend indicates that cameras will produce more and more data that has to be stored quickly. Currently some cameras from Arri, Black Magic & Canon use CFast cards.


CFast cards currently come in sizes from 32gb up to a quarter of a terabyte. That’s right they are available is 256gb sizes. These puppies are pricey costing between $110.00 for 32gb to $675.00 for the 256g. Prices vary depending on size and speed rating. Delkin, Hoodman, Lexar & SanDisk all make high quality CFast memory cards. My personal choice are memory cards from Hoodman. I have been using their cards in CF, SD and now CFast for many years now. I have never had one of their card fail in anyway.