Storage I/O card modes and jumpers

The 2748 and 2778 I/O cards can run in either compression mode or enhanced mode.

• Compression Mode: Compression mode should only be used when you want to run Integrated Hardware Disk Compression. In compression mode, the write cache size is 4 MB.
• Enhanced Mode: Enhanced mode has an enhanced write cache size. In enhanced mode, the write cache size for the 2748 I/O card is 26MB, and the maximum compressed write cache size for the 2778 I/O card is 104MB. Enhanced mode also provides support for Extended Adaptive Cache (by attachment of a read cache device) and Extended Adaptive Cache Simulator.

The following subtopics are included here:

• Setting or changing the mode of an I/O card.
• When an error regarding the mode of the storage I/O card appears, the error message indicates whether the jumper is missing or overridden.
  • If the error message is CPPEA20, the I/O card has overridden the mode set by the jumper. See Mode jumper has been overridden.
  • If the error message is CPPEA21, the I/O card has detected that the jumper is missing. See Mode jumper is missing.