SAS3 Backplaine and HBA Upgrade

[AVSION]

Hi Guys,

It's time to upgrade my FN, i have Purchased a used SM CS846 Chassis that came with SAS846TQ backplane. at the moment i'm using Avago/Broadcom SAS3 9300-i8 HBA that connects straight to my 4TB x 8 HDD and have 6 x SSD plugged directly to the SATA ports on the X10SRi-F MOBO, see full description of my FN in my signature. The Goal is high performance, future proof, reliability and neath solution by using SAS3 throughout to get 12Gbps. i would like your advice of the best option available in my case. here is the two i was thinking about

Option 1 -
Backplane - BPN-SAS-846A + HBA - LSI 9305-24i + 6 x mini SAS HD cables
with this option the downfall is the backplane is 6Gbps and the HBA is 12Gbps and i would need to purchase a new HBA. The pros i will have a direct connection to drives i.e every 4 drives connects to one port on the HBA.

Option 2 -
Backplane - BPN-SAS3-846EL1 + HBA - LSI 9300-8i + 1 x mini SAS HD cable
This is my favourite option i can use my HBA, SAS3 throughout to get 12Gbps, very neath solution only one cable better airflow, however as i'm using one uplink for all drives (MAX 24 when i add more) which will cause a bottleneck and limiting my bandwidth.

please let me know which option i should go with or if there are better options?

Thank you

 

[Constantin]

Seems to me that if you want to avoid the potential for the bus to bottleneck you that you'd want to use a solution that limits the number of drives per "12Gbps bus". This likely will become more apparent as you transition to SSDs, not so much with spinning drives. Thus, I'd file the above option 2) combination away for the day that it may become more acutely relevant. The less expensive one will likely serve you well.

When the time comes to upgrade to SSDs and all that, pull the trigger on the faster bus solution if you find your system to be "bus-bound". Presumably, the price for these HBAs will have fallen by then. Or, you might find that a whole new motherboard with a built-in HBA might make more sense.

 

[AVSION]

Thank you for your reply, i just realised there is an option 3

use my existing BPN-SAS-846TQ REV 3.1 that came with the CS846 Chassis, its a direct attached BPN with 24 dedicated SATA ports. i can use it with HBA - LSI 9305-24i + 6 x mini SAS HD cables to 4 x SATA. if SATA supports 12Gbps i can get full SAS3 bandwidth per port. cabling is not an issue as i already using 2 of the micro cables in a cable sleeve with my 9300-8i HBA, it will be the same for the EL1 cabling. if this is correct it means i'm already future proof for SAS3 SSDs by just upgrading my HBA. Price of the EL1 and 9305-24i is the same but with the HBA i don't have to worry about expender chip limitation as its a passthrough connection. what is your thoughts regarding this option? does someone already using and tested this setup and getting SAS3 Bandwidth?