Connecting LSI to Supermicro Backplane

[nyxynyx]

Hi, I am trying to connect the LSI 9207-8i HBA to the Supermicro BPN-SAS-216A 24-port backplanes which will contain SATA3 SSDs.

Which cable do we need to use, how many cables to use to connect one HBA to the backplane, and how many to be SATA SSD devices can be connected per LSI 9207-8i HBA card?

Thank you!

 

[jgreco]

You need six SFF8087-to-SFF8087 cables, and either three LSI -8i HBA's or one -8i HBA and an SAS expander. Feel free to see the SAS Primer for more details.

Without an expander, you can only connect 8 devices, one to each channel of the HBA (that's the "8" in "-8i").

 

[nyxynyx]

Thank you for the informative article!

Turns out the backplane I have is SAS-216EB which has 1 expander daughterboard (SAS-216EL) attached containing 3 mini SAS ports labelled J1, J2, J3. The manual states that just 1 expander is sufficient to access all 24 drives and supports cascading.

I'm probably wrong, but is it correct to say that when 2 mini-SAS cables are used to connect the 2 ports on LSI -8i HBA card to 2 of the 3 ports on the expander card, we get

• Four 6 Gb/s SAS lanes per cable, for 24 Gb/s per cable
• Eight 6 Gb/s SAS lanes between HBA and expander, for a total of 48 Gb/s between them

Additionally, the manual states that a second expander daughterboard can be attached to the backplane for "failover and recovery". But does it also increase the bandwidth when 2 HBA and 2 expanders are used, where HBA #1 has 2 cables to expander #1, and HBA #2 and 2 cables to expander #2?

• Four 6 Gb/s SAS lanes per cable, for 24 Gb/s per cable
• Eight 6 Gb/s SAS lanes between HBA #1 and expander #1, for a total of 48 Gb/s between them
• Eight 6 Gb/s SAS lanes between HBA #2 and expander #2, for a total of 48 Gb/s between them
• Sixteen 6 Gb/s SAS lanes between both HBAs and both expanders, for a total of 96 Gb/s between them
• Assuming that an SSD has a sustained transfer rate of 500 MB/s, 24 such SSDs are required to hit the theoretical max transfer rates

Thank you!