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Thanks to the group's newly announced CF5.0 specification, CompactFlash cards will move from their present 28-bit addressing, which allows for capacities up to 137GB, to 48-bit addressing. It's said this expanded logical block address space will, at least in theory, allow cards to hold 144PB (that's 144 million gigabytes!) of storage.
There's no suggestion such memory-rich cards can be manufactured anytime soon, but 48-bit addressing also has an immediate, real-world advantage, the CFA adds. A single 28-bit command can transfer only 128KB of data, whereas a 48-bit command can transfer up to 32MB, says the group.
For example, with 48-bit addressing a 4MB picture capture can be reduced to one large data write operating and several small file table updates. With 28-bit addressing, a write sequence of 32 data write and file table updates would have been required, says the CFA.
Improving performance
According to the CFA, CF5.0 now supports the Trim command functionality in Windows 7, whereby the operating system can tell a card which data blocks are no longer in use. Much quicker than an erase operation, a trim command merely removes stale data -- that which had already been marked as deleted by the operating system -- from a card's internal allocation list, the group says.
The CFA says regular employment of Trim will prevent speed from degrading over time, because cards will no longer have to juggle stale data in order to make room for newly written data. Also, it's said, cards will no longer need to copy stale data during their automatic wear leveling operations (via the latter, cards rearrange their data so writes get distributed evenly across the flash medium).
CF5.0 will also include optional "video performance guarantee" solutions, involving a new set of commands that allows a card to inform a host device about its preferred write or read size and alignment, the CFA says. As a result, the group adds, cameras and cards will be marketed with labels such as the following:
The CFA says it has created one logo that will help manufacturers and consumers recognize CF5.0 cards, plus another logo that will identify cards and cameras that come with video performance guarantees. Samples of the logos were not released, however.
Shigeto Kanda, chairman of the board for the CFA, stated, "The higher capacity and higher performance of CF cards enabled by the 48-bit addressing feature in the CF5.0 specification will further increase the value of DSLR cameras. The Video Performance Guarantee feature of the CF5.0 specification will help CF cards to expand into new markets, such as high-speed movie equipment like professional video camcorders."
Further information
The CFA did not provide estimates regarding when CF5.0-compatible cards and host devices are likely to go on sale. An overview of the new specification is available from the organization's website, here [PDF link].
