RAID 1.5 produces a few advantages for mid-range query depths in the fileserver application model. Only when 64 or more sequential blocks are called (typical sequential reading) is RAID 0 able to play its trumps.
Application Performance: Webserver
The webserver profile also shows advantages for RAID 1.5 - this time as clear as day!
CPU Utilization
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Patrick Schmid was the editor-in-chief for Tom's Hardware from 2005 to 2006. He wrote numerous articles on a wide range of hardware topics, including storage, CPUs, and system builds.
So RAID 1.5 won't work because the heads of the disk still need to move to the next data block to read... If you skip blocks, you still have to move past them.
What about RAID 1.5 with Solid State disks. You have nothing to move, yet you can double your read speed with mirroring. Sounds perfect for server caches.
