Do I need a new modem? & is thier speeds of coaxial cable


May 27, 2012
I'm getting a new high-end desktop soon and was thinking about up grading my network the most I can. Currently I'm running on a standard Comcast packege with 20mbps download speed. I'm also using the old RCA model: DHG535-2 modem I all ready understand that I'm best running a wired connection and also understand that my lowest speed component will be my speed but to start. Does it matter what kind of coaxial cable I have. Like in therms of speed or is all coaxial go at the same speed or does it not matter. And does my modem have to be replaced with somthing better or becuse of my service does it not matter. Also I plan on running Ethernet cat5 across my house going along the roof outside is it going to make a difference using cat 6 becuse of my service of 20mbps or should I go cat6. What should I do help?