Block size can be configured through a server OS or file system, and is set to a default size with Oracle databases.
The Sun Flash Accelerator F40 PCIe Card is designed to provide best performance for data transfers that are multiples of 8k size, and using addresses that are 8k aligned. Partitions should be aligned to start on 8k boundaries.
Oracle Solaris OS automatically ensures 8k alignment when the default SMI label type is selected. If a label of type EFI is desired, care must be taken to specify and ensure 8k alignment: the default start sector of 34 for EFI labels is not an 8k aligned value. Use the partition subcommand of the Solaris format command to change the start sector to 48, or any other 8k aligned value. Note that there are 512B per sector.
The ZFS file system automatically aligns partitions to start on 8k boundaries when a full disk is allocated to ZFS (recommended). If you allocate individual EFI partitions to a ZFS pool, ensure the partition is 8k-aligned as discussed above.
For optimal performance of ZFS with the Sun Flash Accelerator F40 PCIe Card, refer to the ZFS Tuning Guide.
For highest performance, verify that the following hardware criteria are met:
The PCI Express slot is PCIe 2.0.
The PCI Express slot has an active width of 8 or 16.
The system meets the physical, environmental, and electrical specifications listed in Card Specifications.
The Sun Flash Accelerator F40 PCIe Card functions in x4 and x2 active width slots, but with reduced performance.
ZFS Tuning Guide: http://docs.oracle.com/cd/E26502_01/html/E29022/chapterzfs-flash.html