Gigabit Network Card

[HuMan321]

I read a post here about someone who runs their HD Homerun straight to a gigabit network card on his server. He stated he did this to keep that traffic off his network which makes sense.
I am wondering if I run my cable from the HD homerun into a gigabit switch and my Sage Server box off the same switch wouldn't that also keep that traffic off the network except for internal to that switch? The patch cords for both connections would be Cat5e.

I am looking to keep traffic down on my network as I have Cat 5 cable installed in my home (Belden-M Datatwist 1583A) I have read everything I can about Cat5 and gigabit, but since I am already wired I am looking to make what I have work. My thoughts are if I can keep most of the heavy traffic local between the server and switch, (all inputs) the other branches should never see over 100 Mbps with the exception of one line which connects this heavy used switch to a 10/100 switch that I am contemplating changing to a 10/100/1000 switch. Maybe worst case I could change this main homerun cable between gigabit switches to Cat5e??? Will comingled wiring like this cause me issues? I am attempting to attach a rough drawing.
Thanks for any help.