Experience with SAS3 attached to Supermicro SAS2 backplanes?

[Pheckphul]

Hello. I'm considering picking up a Supermicro CSE-847E16-R1K28LPB chassis with BPN-SAS2-846EL1 and BPN-SAS2-826EL1 backplanes. I've read that quality SAS2 interconnecting hardware will function at SAS3 when connected to SAS3 storage/HBAs. I am wondering what people's experience has been running SAS3 storage off of these backplanes.


Thank you for your time, and your input will be appreciated.

 

[BlueFox]

You're definitely not going to get SAS3 speeds. That's a limitation of the ASIC in the expander. I have no issues with SAS3 drives with my SAS2-846EL1 backplane and have been running that for years.

 

[Pheckphul]

You're definitely not going to get SAS3 speeds. That's a limitation of the ASIC in the expander. I have no issues with SAS3 drives with my SAS2-846EL1 backplane and have been running that for years.

I was chatting with a person on Discord who said if you force the SAS3 to 12Gb instead of setting to 'auto' SAS3 speeds would be achieved assuming good SAS2 interconnects. Not true?

 

[NablaSquaredG]

It depends.

This might work on a direct attach backplane, where the drives are directly connected to the controller.

The BPN-SAS2-846EL1 backplanes have an expander. That means your connection goes
HBA -> Expander Chip -> Drive

And the SAS2 Expander Chip is definitely not SAS3 capable. Sorry for that.

 

[Pheckphul]

Thank you for the replies guys.