S
EAGATE
X8 A
CCELERATOR FOR
W
INDOWS
U
SER
G
UIDE
, R
EV
. A
30
10.0 A
PPLICATION
N
OTES
10.1
D
ATA
B
LOCK
S
IZES AND
A
LIGNMENTS
The Seagate X8 Accelerator drive exposes 512 byte sectors, but is internally organized in 4K byte sectors (similar to the new
Advanced Format hard drives). This means data writes of blocks smaller than 4096 will involve read-modify-write cycles on
the flash and be correspondingly slower than access of native-block size and above. Reads will be impacted, but at a much
smaller performance penalty.
In addition to using data sizes of 4K bytes or larger, the data blocks themselves should be aligned at 4K boundaries for best
performance.
10.2
IOM
ETER
Seagate recommends using the 2010 version of IOMeter. It is available from the standard IOMeter repository at
Sourceforge.net:
http://sourceforge.net/projects/iometer/files/iometer-devel/1.1.0-rc1/
Other versions of Iometer have limitations which don’t affect hard drive testing but do have a negative impact on the much
higher performing Seagate X8 Accelerator Drive.
N
OTE
For most applications which use the NTFS file system, both of these prior
constraints are automatically met by the file system itself. By default Windows
2008 R2 generates partitions which are properly aligned i.e. on 4KB boundaries,
and NTFS uses 4K allocation units.
