HP DL380p Gen8 8 + w/12 600GB 6G SAS 15K LFF Dual Port wrong SAS cable

Hello all

we have the above hardware here.

HP DL380p Gen8 8-SFF CTO Server

 w/12 600GB 6G SAS 15K LFF Dual Port HDD 7.2TB Bundle with Raid 6.

The read/write performance is  poor.  I tried to 

hdparm -tT /dev/mapper/<logical volume>

Timing cached reads: 15718 MB in 2.00 seconds = 7870.31 MB/sec
Timing buffered disk reads: 526 MB in 3.00 seconds = 175.31 MB/sec

 then, I checked SAS cabling, but seems SAS cabling is wrong as below 

 https://app.box.com/s/tca67904h2tyhy56pdqx

So, I'm planning to change cabling as below

https://app.box.com/s/yz522brh6qpivmcrh89q

it will affect service, but after cabling it can be mounted as is it?

stored data will not affect?

Any idea ?

Thanks in advance
U