Dell T5600 SATA Ports Configuration and Speed

I just purchased a used  Dell Precision T5600 workstation and I'm trying to add three SATA 3 drives, two SSDs and one Western Digital Caviar HDD. The T5600 BIOS version is A11 and I do not plan to use RAID. I am going to do a fresh install of Windows Server 2016.

I'm using the on-board controller, not a PERC card, and I'm having trouble figuring out what the on-board ports are and how to configure them. The motherboard has six ports that all appear to be SATA ports - HDD0 (blue), HDD1, HDD2, HDD3, SATA0 (white) and SATA1. The slimline DVD is currently connected to SATA0.

Page 2 of the T5600 spec sheet says it supports up to two 3.5" or four 2.5" internal SATA, SAS or SSD drives, but has only two internal SATA 6.0Gb/s ports. It doesn't indicate which ports those are.

This Dell KB article updated 4/15/2017 says to connect your SATA drive to the blue HDD0 port.

This Dell KB article updated 8/23/2017 says that the HDD0-HDD3 ports are for SAS drives only, not SATA.

The T5600 Owner's Manual is basically useless.

My questions:

• Which ports are SATA? What are they, SATA, SATA 2, or SATA 3?
• Which ports are SATA 3?
• How should I configure the BIOS for my needs (three dedicated SATA 3 drives, plus the DVD)? 
  • Should the Boot sequence be UEFI or Legacy?
  • Should the AHCI Operation be set to ATA or AHCI?
  • Any other settings?
  • Any reason I shouldn't upgrade the BIOS to A15 when I get it running?

I also have a PCI SATA 3 controller with two internal ports I can throw in it, so I can run all three drives at SATA 3 speeds.

Thanks!