The bigger problem with system utilization for software RAID is the cache, not the CPU cycles proper. Simply preparing to write 1 MB of data will flush half of a 2 MB L2 cache. This hurts overall system performance far more than the few microseconds that XORing the data takes.
(A similar effect occurs with file system buffering, and this is one reason why direct I/O is attractive for databases — there’s no pollution of the system cache.) This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
