IOMeter is an I/O subsystem measurement and characterization tool for single and clustered systems. It is used as a benchmark and troubleshooting tool and is easily configured to replicate the behaviour of many popular applications. One commonly quoted measurement provided by the tool is IOPS.
IOMeter allows the configuration of disk parameters such as the ‘Maximum Disk Size’, ‘Starting Disk Sector’ and ‘# of Outstanding I/Os’. This allows a user to configure a test file upon which the ‘Access Specifications’ configure the I/O types to the file. Configurable items within the Access Specifications are:
- Transfer Request Size
- Percent Random/Sequential distribution.
- Percent Read/Write Distribution
- Aligned I/O’s.
- Reply Size
- TCP/IP status
Using Iometer to get a more precise gauge on the performance, we can once again see that the SX300, even at 3Gbps speeds is still able to deliver around twice the read IOPs that ADATA rate the drive for.
The slower connection speed however does seem that have a notable impact on the write performance, with just under half the rated performance recorded.