The proposed new format, which doesn't yet have a name, supports data transmission at up to 500MBps, the three companies said in a joint statement. This is roughly three times faster than CF6.0, the latest version of the CompactFlash-card format that was announced in mid-November.
The faster speed enables continuous RAW image shooting because it widens the bottleneck between the camera and memory card.
When images are being snapped continuously they must be quickly written to the memory card to clear the camera's internal buffer memory and make room for the next shot. RAW images present a particular problem because they are several times larger than JPEG images so the time taken to write them to the card is longer.
This mismatch between the camera's shooting speed and the rate at which it can store the images is often the reason continuous shooting is limited to a set number of shots.
Behind the big jump in the cards' speed is a switch from the parallel ATA interface to the faster PCI Express, which has already been widely adopted in personal computers.
Cards for the new specification will look similar to CompactFlash, but will have some differences. There is no backwards compatibility with CompactFlash cards used until now.
The CompactFlash Association has already made one attempt to introduce faster cards without backward compatibility: the CFast specification defines cards that are electrically compatible with the SATA (Serial-ATA) interface, but have the same shape and connectors as CompactFlash cards. Version 1.0 of CFast was released over two years ago, but camera manufacturers have not yet released compatible products.
The new format proposed by Sony, Nikon and SanDisk is not just intended for cameras. Use of the PCI Express interface should also speed up transfer of images from a card to a personal computer.
The specification includes cards up to 2 terabytes in capacity, so its backers are also promoting it for adoption in other high-volume, high-speed data storage applications such as high-definition video.
The format appears to already have the support of the CompactFlash Association (CFA).
The statement from the three companies included a quote from the CFA's chairman, Shigeto Kanda, in which he said the format would "enable further evolution of hardware and imaging applications". Shigeto's CFA work is alongside his job at digital-camera maker Canon.
It's not clear when it will be standardised and begin appearing in cameras although a spokeswoman for Sony said it shouldn't be too long.
"We're not talking about years," said Yoko Yasukouchi.