SAS-3 vs SAS-2 HDDs

Question

What are the main differences between SAS-3 and SAS-2 HDDs? Are there performance differences? Suppose we are talking of 10k rpm disks, ~1 TB, in both cases.

Regards,

Solution 1

No. There are no performance differences with that disk type/speed/capacity. Perhaps with an SSD, but for your 7,200/10,000 RPM use case, no.

The SAS specification has a roadmap and the connection fabric is changing while the drive mechanics remain much the same.

Solution 2

SAS-3 supports 12 Gbps while SAS-2 supports 6 Gbps. Many people say that using 12 Gbps disk drives is of no use in present architectures unless there is a flash cache layer in between. 12 Gbps interface can be used with an SSD. See the wikipedia entry on serial attached SCSI.

Comments

[Chopper3]

By the way they're not really known as SAS-3/SAS-2 like SATA is, although I can understand why you would - it's more typical to see 6Gbps SAS/12Gbps-SAS etc.