Hello,
Your MB has 6 SATA II connectors (blue color) that are part of the PCH chipset, and theoretically have transfer rates of ~ 2400 Mb/s, or ~ 800 MB/s. You new WD Blue drive has a average transfer rate of slightly less than 100 MB/s, so there is nothing to worry about saturating your regular SATA II connectors. It will never happen. I would forget about the Marvel separate chip, and use the Intel SATA II connectors, where you can just connect your HDD's or SDDs and they will just work. No drivers to install, no Marvel chip drivers to worry about, or problems with it. You didn't say how many drives you presently have connected, but as Basic Drives, no RAID, you should be fine!