Adaptec RAID 2100S Software User's Manual page 58

Although arrays must be built from drives that are all attached to
the same controller, arrays can contain drives from multiple
channels. The approach is slightly different for each controller
model:
Adaptec 2400A
Adaptec 2100S
Adaptec 3200S/
3210S/3400S/3410S
Supports one drive per channel, for a total of
four drives; therefore, any RAID array involves
spreading the drives across channels.
Provides a single channel with support for up
to 15 devices.
Arrays are built using the drives in the order
selected, regardless of channel. Provides multi-
channel performance benefits over single-
channel controllers. Also, multiple channels can
be used to create fault-tolerant arrays using
pairs of drives on alternate channels.
Storage Manager
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