HP NetRAID 1 Controller - Manual (Page 84)

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Wide SCSI: A variant on the SCSI-2 interface. It uses a 16-bit bus, double the width of the original
SCSI-1, and therefore cannot be connected to a SCSI-1 bus. It supports transfer rates up to 20 MB/s,
like Fast SCSI.
Write-Through/Write-Back: When the processor writes to main memory, the data is first written to
the cache on the assumption that the processor will probably read it again soon. In a "write-through"
cache, data is written to main memory at the same time as it is cached. In a "write-back" cache it is
only written to main memory when it is forced out of the cache. Write-through is simpler than write-
back because an entry that is to be replaced can just be overwritten in the cache, as it will already
have been copied to main memory. Write-back requires the cache to initiate a main memory write of
the flushed entry followed (for a processor read) by a main memory read. However, write-back is
more efficient because an entry may be written many times in the cache without a main memory
access.