This article is profoundly simplistic, and does not take into consideration numerous factors that include
1) Degraded performance - How does a SATA vs a SAS array perform when a bad block is encountered or when there is degradation due to a failed disk
2) Data corruption - SAS disks typically have 10X or greater number of ECC bits then SATA drives. With multi TB arrays, you pick up ECC errors quite frequently
3) Drive controllers matter. More intelligent controllers with larger cache will generate fewer I/Os to disk as they coalesce I/O requests. Furthermore, the added intelligence that the Cache control mode page (08h) provided in disks that use the SCSI protocol allow for tuning that one can not do with SATA disks.
As such, for almost any given load, one can tune SAS disks to do fewer I/Os.
This paper considers I/Os to be absolute and not affected by the drive technology. That is simply not the case.
Finally IOMETER does NOT analyze I/Os that are actually performed by the disk drive. While it is a nice tool, it can not be used to measure physical disk I/Os. It only measures I/O requests sent by high level read/write requests. It is also incapable of measuring actual I/Os performed by the disk drives behind a RAID controller.
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