SC846 HBA to backplane question

[Sittingmongoose]

I am looking at getting a SC846 with a BPN-SAS-846A backplane. As I understand it, the BPN-SAS-846A has 3 8087 connectors on it? If I run a 9300-8i which only has 2 connectors on it, does that mean I need a second HBA to use all 24 drives? I was hoping to run in SAS3.

Also, are the 9311 and 9300 the same? I cant find any differences online.

 

[i386]

The 846A backplane has 6x sff8087 connectors. You will need 3 hbas with 2x sas multlane ports

 

[BoredSysadmin]

are you planning to connect hard drives or SSDs? If prior then, by all means, you could get SAS port multiplier and a single HBA

 

[Sittingmongoose]

I am going to have a lot of IO and many of the disks being accessed at the same time. Probably dont NEED SAS3, but I want the room to grow.

I wish SAS3 Multipliers were cheaper or there were SAS3 HBA cards with more than 2 ports!

 

[nthu9280]

There are SAS3 4 port HBAs that can support 16 drives. but they are not cheap. If you are primarily using mechanical drives, no real benefit of going with SAS3 and paying the premium. You can get HP H220 or Dell 9217-8i which are based on LSI SAS2308 controller that supports PCIe Gen 3.0 and has higher IOPS. They can be had for $35-40 range. OTH, if you have multiple SSDs in the mix, SAS3 controllers can provide the benefit.

 

[Sittingmongoose]

There are SAS3 4 port HBAs that can support 16 drives. but they are not cheap. If you are primarily using mechanical drives, no real benefit of going with SAS3 and paying the premium. You can get HP H220 or Dell 9217-8i which are based on LSI SAS2308 controller that supports PCIe Gen 3.0 and has higher IOPS. They can be had for $35-40 range. OTH, if you have multiple SSDs in the mix, SAS3 controllers can provide the benefit.

Thanks, I saw the LSI 9207-8i. Probabaly going to grab that until sas3 backplanes are cheaper for the sc846. It’s worth an extra 10-15$ to get the LSI over the dell so I don’t have to worry about flashing the card to it mode.

 

[nthu9280]

Make sure the chip is SAS2308 D1 stepping. There are two different steppings in the wild - C0 and D1. C0 will only work at PCIe 2.0 speeds. I'd be leary of LSI especially if it's listed as new due to the counterfeit issue. Flashing the 2308 based controllers is straight forward compared to Dell H310/H200 etc that are based on SAS2008 controller

 

[Sittingmongoose]

Make sure the chip is SAS2308 D1 stepping. There are two different steppings in the wild - C0 and D1. C0 will only work at PCIe 2.0 speeds. I'd be leary of LSI especially if it's listed as new due to the counterfeit issue. Flashing the 2308 based controllers is straight forward compared to Dell H310/H200 etc that are based on SAS2008 controller

Those are both great points. I guess it’s better to grab a dell 9217-8i then. Thanks for the heads up!!

 

[ari2asem]

BPN-SAS-846A is sas-2 (or 6gbps) backplane without expander and support maximal 24hdd/ssd. . so, you need 6 ports of sff-8087 to connect to the backplane. this backplane isn't sas-3.

and about hba....maybe adaptec 78165 is something for you?
https://adaptec.com/en-us/support/raid/sas_raid/asr-78165/

it has 2 internal sff-8643 and 4 external sff-8644 ports (so total of 24hdd) of speeds sas-2. and it has fan connecting port, 3 pin.
one disadvantage...you have to reroute external cables back to internal backplane

 

[Sittingmongoose]

BPN-SAS-846A is sas-2 (or 6gbps) backplane without expander and support maximal 24hdd/ssd. . so, you need 6 ports of sff-8087 to connect to the backplane. this backplane isn't sas-3.

and about hba....maybe adaptec 78165 is something for you?
https://adaptec.com/en-us/support/raid/sas_raid/asr-78165/

it has 2 internal sff-8643 and 4 external sff-8644 ports (so total of 24hdd) of speeds sas-2. and it has fan connecting port, 3 pin.
one disadvantage...you have to reroute external cables back to internal backplane

I would only run the 846A if I could run SAS3, other wise ill just use the EL1. After a lot of research, I think I landed on using the EL1 and a Dell 9217 HBA(Highest IOPs SAS2 card ive seen).

 

[i386]

The "A" backplanes are passive, they don't have logic and connect wires 1 to 1 from hdds/ssds to hba/raidcontroller

 

[nthu9280]

BPN-SAS-846A is sas-2 (or 6gbps) backplane without expander and support maximal 24hdd/ssd. . so, you need 6 ports of sff-8087 to connect to the backplane. this backplane isn't sas-3.

and about hba....maybe adaptec 78165 is something for you?
https://adaptec.com/en-us/support/raid/sas_raid/asr-78165/

it has 2 internal sff-8643 and 4 external sff-8644 ports (so total of 24hdd) of speeds sas-2. and it has fan connecting port, 3 pin.
one disadvantage...you have to reroute external cables back to internal backplane

While SAS-846A (or TQ) is not officially certified as SAS3, They work fine with SAS3 speeds.

If one is going Adaptec route, ASR-71605 are available for $60 OBO instead of the 78165 and cable routing issues.

Just need 8643 > 8087 or 8643 > 4 x SATA depending on the A or TQ backplane.

asr-71605 | eBay

 

[Sittingmongoose]

While SAS-846A (or TQ) is not officially certified as SAS3, They work fine with SAS3 speeds.

If one is going Adaptec route, ASR-71605 are available for $60 OBO instead of the 78165 and cable routing issues.

Just need 8643 > 8087 or 8643 > 4 x SATA depending on the A or TQ backplane.

asr-71605 | eBay

Since that Adaptec solution doesn’t provide SAS3, I think I’ll stick to the El1 and just use 1 cable.

Thanks though it’s great to know that’s out there!

 

[ari2asem]

While SAS-846A (or TQ) is not officially certified as SAS3, They work fine with SAS3 speeds.

If one is going Adaptec route, ASR-71605 are available for $60 OBO instead of the 78165 and cable routing issues.

Just need 8643 > 8087 or 8643 > 4 x SATA depending on the A or TQ backplane.

asr-71605 | eBay

71605 is 16 port. 78165 is 24 port

but EL1 is good choice

 

[kapone]

In a homelab...SAS3 is way overrated, just like 40gbe...

There are very very few people who can actually use that much bandwidth. SAS2 is perfectly fine for 99.99% of the folks here. Remember each SAS2 port is 4x i.e. 24gbps. That's...~2.4GBps...that's...a LOT of bandwidth. The only case where that is restrictive is RAID set(s) of SSDs, and not that many people use them, and even if they do, a majority of them want it, they don't need it.