HP 418371-B21 - Dual Port 72 GB Hard Drive, Technology Brief, Page: 6 / 14

Figure 2. Relative performance: random operations of non-NCQ SATA, NCQ SATA, and SAS 2-drive
array with HP Smart Array Controller P400 Controller, RAID 1
Random Operations, RAID 1 (128 KB)
0%
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700%
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4KB RANDOM READ 4KB RANDOM WRITE 4KB OLTP 8KB RANDOM READ 8KB RANDOM WRITE 8KB OLTP 64KB RANDOM READ 64KB RANDOM WRITE
REL
A
T
IVE PERF
O
RM
ANC
E (%)
IOMETER 07.30.2004
SATA, Non-NCQ 60-GB, 5.4K, 25/75 R/W cache (baseline performance level)
SATA, NCQ 120-GB, 5.4K, 25/75 R/W cache
SAS, 72-GB, 15K, 25/75 R/W cache
The HP P400 controller supports NCQ, so the NCQ SATA drives provide an increase in performance
over non-NCQ SATA drives. The SAS arrays, however, are much faster than either of the SATA
arrays and exhibit a substantial performance increase for most operations.
Figure 3 compares the throughput performance of the SATA and SAS drives in the same
configuration, and illustrates the substantial improvement of SAS drives.
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