Looking at those drives as well I doubt that they would saturate the 6gbps.  I personally think you would get along fine using those in the current setup.  The 12gbps interface is much more for the speed of SSDs and most HDD manufactures just use the 12gbps interface since it is now the standard even if it doesn't actually benefit the speed of the drive.
Hello, Community; We have recently replaced our VM Host, and I now have this T620 unused. I would like to create a TrueNAS server, but wondering if it is possible to upgrade this server to 12 GB/s and have a few questions.This server has the 12 3.5" bay option, any help with the questions below would be appreciated: Perc 710 P raid card - I would replace this with an LSI True nas capable HBA 12 GB/s RAID Card. 1a.) Will the T620 backplane support 12 GB/s? PCIE-3.0 on the Mainboard according to documents, not sure if this is relevant.1b.)Would i need to swap out the cables to the backplane? 2.)I plan on booting to raid 1 ssd boot 6 GB/s and using 12 GB/s 3.5" WD Reds for NAS pool. will this work? specifically would the fact that the ssd's are in the backplane bays interfere with getting 12 GB/s on other drives?Any assistance is appreciated.
T620 Perc H710P Upgrade to 12 GB/s??