Performance factors for HP ProLiant Serial Attached Storage (SAS)

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Performance comparison between SATA and Midline SAS drives
Systems supporting SAS can configure a mix of SAS and SATA drives, but you can more easily
achieve your performance goals using SAS drives. You cannot mix SATA and SAS drives within a
logical drive.
Figures 1 through 3 are plots of performance data from benchmark tests of SATA drives and Midline
SAS drives using the following configuration:
 System—HP StorageWorks D2600 Modular Smart Array
 SAS Controller—HP Smart Array P411, firmware version 3.50, 512 MB cache, RAID 0
Figure 1. Sequential Read operations with HP Smart Array P411 Controller, RAID 0.
Figure 1 above compares read performance between an array of midline SAS drives to an array of
midline SATA drives. Results indicate an array of 6Gb SAS drives can read a single stream of data at
a rate of more than 1.6 GiB/s, as compared to an array of SATA drives reading at a rate of less than
1 GiB/s. The performance difference is due to the SATA interface being less efficient than a SAS
interface. The SATA interface can only run at 3 Gb/s even if the attached drives are rated to higher
speeds, whereas the SAS controller runs at 6 Gb/s with 6Gb SAS drives.
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4KiB 64KiB 256KiB 512KiB 1MiB
Midline SATA
Midline SAS
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Sequential Read, RAID-0, 12 Drives