HBA Breakout For (Half) Dummies?

[patrickjp93]

So, how does a 16-port HBA card support "up to 240" devices? We've all seen the 1x to 4x breakout cables, but afaik, you can't just daisy chain them in any sort of prosumer setup. If I wanted to get the 4-port version of this card that can support up to 64 devices, and only attach 8 drives with room for expansion, what would be the recommended approach in a con/pro-sumer PC case?

Looking at the Storinators from 45Drives and similar enterprise racks, there are semi-custom backplane PCBs and controllers attached to a pair of SAS ports through each for link redundancy, or 2 breakout cable channels per backplane controller. Is there a prosumer-accessible way of doing this?

 

[HoneyBadger]

What you need are called "SAS expanders" and they can either be integrated directly into a disk backplane or available as standalone cards such as the HP example below.

https://www.amazon.com/gp/product/B...=1789&creative=390957&creativeASIN=B0025ZQ16K

Unlike SATA port multiplication, SAS expansion is much more supported, and behaves similarly to network switching.

 

[patrickjp93]

What you need are called "SAS expanders" and they can either be integrated directly into a disk backplane or available as standalone cards such as the HP example below.

https://www.amazon.com/gp/product/B...=1789&creative=390957&creativeASIN=B0025ZQ16K

Unlike SATA port multiplication, SAS expansion is much more supported, and behaves similarly to network switching.

In my instance I'd be looking for a case-mountable PCB rather than a PCIe card (primarily due to the cost of 10GBe MITX boards vs. ATX and SSI-CEB+), something like this, but potentially far less extravagant depending on what's cost-effective. IDK, get a single U.2 connector to break out to 32 drives off of one expander, or 2 connectors breaking out to 2 16-drive expanders each?

 

[HoneyBadger]

In my instance I'd be looking for a case-mountable PCB rather than a PCIe card (primarily due to the cost of 10GBe MITX boards vs. ATX and SSI-CEB+), something like this, but potentially far less extravagant depending on what's cost-effective. IDK, get a single U.2 connector to break out to 32 drives off of one expander, or 2 connectors breaking out to 2 16-drive expanders each?

You won't be using U.2, that's for NVMe cards. The ports on the expander linked are SFF-8087, and it looks like that expander can take a single input (4 lanes) which is 4x600MB/s or 2.4GB/s. If you plan to use a large number of SSDs, then you'll want to use multiple expanders with fewer drives, as 24 SSDs will easily overwhelm that, but spinning drives shouldn't pose a serious issue. If the expander can do 8 lanes of input that would be better.