Boot Question

Greetings all - it has been awhile since I've been here. I'll need to help more in the future.

I have a Dell XPS 8500 with an i7 processor and 24GB of Ram. It came with a 2TB hard drive and a 256 SSD drive on the motherboard. I installed Win 7 Ultimate on the SSD and used it as my primary drive leaving the 2TB "C" dive for storage. The C drive does have Win 7 installed as well.

Now I replaced the C drive with a Samsung EVO 850 SSD on which I installed Win 8.1 - works great. To get another SATA III connection I installed a PCIe internal 2 port SATA III to which I connected the 2TB hard drive which I plan to just use as storage.

Now here is my quandary - after adding the 2TB drive back, all three drives work but the boot time on my main "C" drive (Samsung EVO 850) has slowed and I can not figure out why. Somehow the 2TB drive has slowed it down.

Forgive me for such a trivial question but does anyone have a suggestion as to the cause of the slow down? Might it be in my BIOS? I do have the "fast boot" option checked on the SSD with win 8.1. I'm a speed junkie - what can I say?

Thank you,

BillC