SAS Interface Full interconnect guide (bottom)

Disk back panel: Eclectic

In the tower server where the rack server or the hard drive slot is higher, the SAS Hba/raid card is generally not connected to the hard drive directly with the SAS cable, but through the disk backplane to facilitate the hard drive Plug and unplug. Disk Backplane is also a typical internal connection application, one side of the hard drive, the other side even Hba/raid card. Drive-side say, unified as a SFF-8482 socket, SAS and SATA drives are available, and generally better than developing a single back panel that only supports SATA drives. PCB and wiring is clearly not our focus, the main variables in the cable from the Hba/raid card connected to the "host-side connector."

Host-side connectors and drive connectors are usually on both sides of the disk backplane, but also on the same side, such as the white SFF-8484 connector (even the SAS Hba/raid card) in the image above, and the two black SFF-8482 connectors (even the hard drive) that the arrows point to.

Since to connect through the cable and Hba/raid card, host-side connector selection is also the same as the first two pages introduced so several, the biggest difference lies in the layout of the changes-from the original "lying" in the Hba/raid card PCB, instead of "Stand up", that is, perpendicular to the disk backplane. Do not underestimate the difference, saying that it affects at least one of the connectors of the fate is not too much.

SATA style connectors, SAS 4i (SFF-8484) connectors, and mini SAS 4i (SFF-8087) connectors are placed vertically on the disk Backplane

Like the SAS Hba/raid card, the disk Backplane was originally used as a SATA style connector on the host side. Because it is placed vertically, a sheathed SATA style connector has a small footprint and is almost negligible relative to the size of the disk backplane, as is the case with the Supermicro SAS825TQ backplane, mentioned on page 3rd of this article, with 8 SATA style connectors, or even 16. However, many cables and clutter, PCB cabling and other SATA style connectors inherent problems are unavoidable-after all, for SAS, SATA style connectors is only a transitional solution, there is no need to exist now.

If you "stand" on the disk back panel, SFF-8484 (middle) is not inferior to SFF-8087 (right) how much

The next is still the SFF-8484 connector. As we said before, SAS 4i the biggest crime is too occupy the SAS Hba/raid card PCB space, but that is in it "down", plug the direction and PCB parallel. When the SFF-8484 plug is erected, the width remains, but the thickness is only flat with the SATA style connector with a sheath, less than the SFF-8087 socket. As for the height, the SFF-8484 socket is lower than the SFF-8087 socket, in a combination state (plug into) is only roughly equivalent. In general, the characteristics of the disk backplane to cover the SFF-8484 connector, the advantages of SFF-8087 connector is far from the SAS Hba/raid card Obviously, this is probably the SFF-8484 has not yet been "sitting can" SFF-8087 elimination of the main reasons.

On the left is the IBM ServeRAID 8i SAS RAID card provided by Adaptec for the IBM xseries 460 Server, the two SFF-8484 sockets are placed vertically on the PCB for horizontal installation, and the footprint is significantly reduced-however, this practice is not universal, Since most SAS Hba/raid cards are designed to consider adjacent PCI slots, the SFF-8484 sockets must be placed parallel to the PCB, and the upper right is the SFF-8484 connector on the IBM xseries 460 Server disk Backplane