Not sure where to post, so here it goes:  Now that i stopped using the two mb marvell SATA ports, i have only 14, and they are full.  I have a new drive that i need to preclear before i add it to my array.  Can i do that on the marvell port and then transfer it to another port when i replace a drive?  

 

Im in a bind because my power supply doesnt seem to be able to handle a second 8 port controller, and i dont need 8 more ports anyway.   

 

the new drive is an exchange from an rma - can i assume its good and just swap it in?  Seems risky to me...

If I understand you correctly, you are not going to add that new drive, instead you are going to use it to replace a drive.

 

Preclear isn't required, and it is really only for testing a disk since Unraid will clear a disk itself in the one and only scenario where a clear disk is needed, when adding to a new data slot so parity will remain valid.

 

There are other ways to test disks. You can test them on another computer using the manufacturers test software, for example. Or go ahead and use one of the Marvell ports since there is no data at risk for that disk.

 

Another thing you can do that sometimes helps with Marvell is to disable IOMMU in the BIOS if you aren't using it for VMs.