Not every step forward for technology is announced with fanfare, huge product roll-outs, and a gigantic media blitz. Some advances are very quiet, like the shipment of the very first line of memory cards based around the new X4 technology. SanDisk (via Electronista) just started sending out their new line of standard SDHC and Memory Stick Pro Duo cards, which use 4 BPC storage as opposed to the standard 2 or 3 BPC.

BPC stands for "bits per cell". The increase to 4 BPC should allow for smaller 8 GB and 16 GB chips, and will scale to allow for 64 GB and larger capacity SDHC chips in the near future. The coming of 4 BPC technology will also have reprecussions in the world of solid state drives, as SSDs also use multi-level cell storage.

Currently, SanDisk only offers 8 GB and 16 GB 4 BPC cards. Prices are not out yet, but they could very well end up costing the same as the current 8 and 16 GB cards on the market. Both cards are heading to stores in SDHC and Memory Stick Pro Duo versions, so we should know for certain soon.