How to reach 2GB/s on SAS 12Gbps interface

[h1ggsboson]

Hello!
I was lucky enough to buy 2 PM1643 7.68TB each for a bargain and I've just installed them into my system. They are great, but I feel I'm leaving performance on the table, and it seems wasteful.

Here's the official Samsung specification: https://www.samsung.com/semiconduct...Product_Brief_Smasung_PM1643_SAS_SSD_1805.pdf
They claim the sequential read/write speeds are ~ 2000MB/s, but the drives use a SAS 12 Gbps connection, which should only support 1000MB/s.
I'm connecting the drives to a H240 HBA using a cable like this one: Cablu mini SAS SFF-8087 la 4 x SAS SFF-8482 + alimentare 50cm, Delock 83059 (SFF-8087 to 4x SAS SFF-8482)



When I run

ssacli controller slot=0 show ssdinfo detail

I get

         PHY Count: 2
         PHY Transfer Rate: 12.0Gbps, Unknown
         PHY Physical Link Rate: Unknown, Unknown

, which suggests I'm not wiring the SSDs fully, but there's no extra SFF-8482 connector to hook to.

When I'm benchmarking the drives, I see 1000MB/s read and write, as expected.
How can one achieve Samsung's claimed 2000MB/s through the 12Gbps interface? I'm pretty sure it's got something to do with the dual-port and I'm not connecting the drives correctly.

Many thanks!

 

[BlueFox]

Dual port is indeed the answer. You'd be able to achieve that using MPIO.

 

[h1ggsboson]

Thank you for the answer, BlueFox! Is a different cable needed as well? Something like this one: Cablu Dell Mini SAS Dual SAS T3600 H200 H310 H700 H710P 0T3F4V T3F4V

 

[Rand__]

Yes, that one should work.