Hi,
I made the following observation, and I cannot understand how this works.
For example:
a) the Supermicro backplane BPN-SAS-825TQ can hold 8 SATA or SAS disks. On the rear, it has one individual connector for each disk. However, these connectors are SATA (male). How can this work? the SATA connector has less signals on it than SAS. But according to the datasheet, the backplane can work with SAS disks (provided the correct HBA is used).
b) I was looking for cables to install one SAS disk in my PC. My HBA has one SFF-8643 connector. However, all the cables I found so far that have an SFF-8643 on one end, have either a SFF-8643 on the other end too, or SATA connectors (female). Again, why SATA connectors? aren't there signals missing on that connector?
and then, to connect to the disks, I found an adapter piece (it seems to be really only a mechanical adaptor) that plugs into the SAS disk, and at the other end has a SATA connector (male) and SATA power connector.
So apparently, if I want to use a SAS disk, I need a csble for my HBA that has SFF-8643 on one end and a female SATA connector on the other end. And I need this mechanical adapter piece that plugs into my disk and provides a male SATA connector on the other end.
I know that somehow SATA and SAS are similar, as a SATA disk can be run on a SAS controller (but not the other way round) but I don't understand why the backplane and practically all cables I found have just SATA connectors. I could not find one single cable with a SAS connector for the disk and I wonder why this is so. Can somebody explain?
thanks!
I made the following observation, and I cannot understand how this works.
For example:
a) the Supermicro backplane BPN-SAS-825TQ can hold 8 SATA or SAS disks. On the rear, it has one individual connector for each disk. However, these connectors are SATA (male). How can this work? the SATA connector has less signals on it than SAS. But according to the datasheet, the backplane can work with SAS disks (provided the correct HBA is used).
b) I was looking for cables to install one SAS disk in my PC. My HBA has one SFF-8643 connector. However, all the cables I found so far that have an SFF-8643 on one end, have either a SFF-8643 on the other end too, or SATA connectors (female). Again, why SATA connectors? aren't there signals missing on that connector?
and then, to connect to the disks, I found an adapter piece (it seems to be really only a mechanical adaptor) that plugs into the SAS disk, and at the other end has a SATA connector (male) and SATA power connector.
So apparently, if I want to use a SAS disk, I need a csble for my HBA that has SFF-8643 on one end and a female SATA connector on the other end. And I need this mechanical adapter piece that plugs into my disk and provides a male SATA connector on the other end.
I know that somehow SATA and SAS are similar, as a SATA disk can be run on a SAS controller (but not the other way round) but I don't understand why the backplane and practically all cables I found have just SATA connectors. I could not find one single cable with a SAS connector for the disk and I wonder why this is so. Can somebody explain?
thanks!