Why are the disks connected to the controller not at full speed?

Question

linux

There is a server hp dl180 g6 with sas on 12 disks 3.5 inches.
There are 6 HP EF0300FARMU and EF0300FATFD 15000 rpm drives connected to an HP Smart Array P410 controller.
According to the specification https://www.hpe.com/h20195/v2/GetPDF.aspx/c04111713.pdf there is support

6Gb/s SAS technology delivers high performance and data bandwidth and contains full compatibility
with 3Gb/s SATA technology.

Why then does hpssacli ctrl all show config detail show the following information for drives?

physicaldrive 1I:1:2
         Port: 1I
         Box: 1
         Bay: 2
         Status: OK
         Drive Type: Data Drive
         Interface Type: SAS
         Size: 300 GB
         Drive exposed to OS: False
         Native Block Size: 512
         Rotational Speed: 15000
         Firmware Revision: HPD6
         Model: HP      EF0300FARMU
         PHY Count: 2
         PHY Transfer Rate: 3.0Gbps, Unknown
         Sanitize Erase Supported: False

How to achieve PHY Transfer Rate: 6.0Gbps, Unknown?

Answer 1

Check the controller settings and jumpers on the drives. And there and there it is possible to set the exchange rate.

Answer 2

backplane problem. it's 3Gb/s and you can't do anything about it. faced the same problem on an old intel server.