SA-P420 Controller supports up to 27 drives depending on the server implementation.
6Gb/s SAS [(600MB/s bandwidth per physical link)]
x8 6Gb/s SAS physical links (compatible with 3Gb/s SATA )
512 MB 72-bit wide DDR3-800MHz flashedback write cache 1 GB 72-bit wide DDR3 1333MHz flash backed write cache or 2GB 72-bit wide DDR3-1333MHz Flash Back Write Cache provides up to 4.2 GB/s maximum bandwidth
x8 PCIe 3.0 host interface provides maximum bandwidth Gen 3.0
Read ahead caching
Write-back caching (with FBWC)