While the current CD format is tied to 44.1 kHz sampling rate, SACD samples at 2.8224 MHz. Also, with a storage capacity of 4.7 gigabytes per disk (as much as a DVD), SACD can accommodate separate stereo and six-channel mixes of 100 minutes each. The SACD format also has the capability to display photo and text information, such as liner notes, but this feature is not incorporated into most discs.
SACD players are backward compatible with conventional CDs, and some SACD disks are dual-layer discs with PCM content that can be played in standard CD players. In other words, the same disk can hold both current CD versions of the its SACD content. That means that you can invest in dual-format SACD's to play on your current CD player and then access the SACD content on the same disc later on an SACD-compatible player.
It must be noted that not all SACD discs have a standard CD layer - which means you have to check the disc label to see if a specific SACD disc can also play on a standard CD player.
SACD's can come in either 2-channel or multi-channel versions.