Question How to fix poor drive performance / complete failure ?

Mar 26, 2020
We are having issues connecting hard drives to one of our servers. The motherboard has 6 SATA ports. 2 - 6gbps, and 4 - 3gbps. If we connect a drive to one of the 6gbps ports, the server will either not boot, or the disk is inaccessible in Windows. We connected 4 drives to all of the 4 - 3gbps ports, and they do not throw any errors, however they can't sustain useful write speeds (approx. 20Mbps). One of the drives which is our Replica target was timing out as well. When disconnecting one of the drives, the write speed increases to 160Mbps, the Replica target stopped timing out, however we then see multiple errors: "The device, \Device\Harddisk3\DR3, has a bad block." Any suggestions as to what could be causing this ?