Setting up Netgear modem with Comcast modem/router? Splitter?

[Dioxyde]

Hey guys, appreciate your attention here. I'm a Comcast customer who currently uses the Xfinity modem/router all-in-one for internet access. I would to change this so that my Netgear cm500 is the acting modem, but I'm confused on how to still have wireless to the rest of the house. The Xfinity modem acts as a router as well, is it possible to to use the Ixfinity as simply a router? I read something suggesting I would need a splitter to do this, but won't that degrade the signal? Would that only be to make the Xfinity work as a router? If I purchased a dedicated router that isn't a modem too would I still need a splitter?

Really unaware about how modems and routers work, dunno what cables I need or if I have to get a separate router entirely. Thank you much for any advice!

Here's the two products I mention:

https://www.amazon.com/gp/product/B00R92CEVU/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

http://www.newegg.com/Product/Product.aspx?Item=N82E16833588001&nm_mc=KNC-GoogleAdwords-PC&cm_mmc=KNC-GoogleAdwords-PC-_-pla-_-Modems-_-N82E16833588001&gclid=Cj0KEQjwqfvABRC6gJ3T_4mwspoBEiQAyoQPkS8-BSK2PcFzJycVd3qlgRuzswP15C1ItiCWPFMHXJIaAoTe8P8HAQ&gclsrc=aw.ds

[Geek-9pm]

Hello, here is my short answer. I have been there and done that. Forget about it.
Some detail: Comcast, like many other service providers, want to protect their own interests while giving users a good service. Unless you can prove to the technical people at Comcast that you really have to have a different router, they're going to say definitely not.
The Internet service providers have an agreement where you will use their service for just your own household and a limited number of devices in your household. Using an additional router is practically inviting the whole world into your Internet connection. The Internet provider wants to know what password you are using and whether or not that password is very secure. They do not want you to use another form of Wi-Fi interface that would be less secure. Adding Wi-Fi boosters or range extenders also is a concern for the Internet service provider. The end-user license agreement specifically prohibits you from reselling or even giving away Internet service to other people outside of your business or family plan.
Now, having said that, there are a few ways they may allow you to extend your wireless coverage. The most obvious thing to do is to have your Comcast wireless router move to a central location inside of your house and possibly had elevated position so they can give best possible coverage to your entire house. After that, you might be able to use a wireless repeater to boost the signal level in one corner of your residence or place of business.
Again, let me repeat this idea. Using another router is just another thing that you're Comcast provider does not want to have to think about. The net gear router has just too many options and possibilities it could drive your Internet service provider crazy trying to figure out what you're trying to do.
Which brings up the question, what really are you trying to do? Do you really think you need a better router? Why? The insanity wireless router is capable of doing Wi-Fi connections at 150 Mb per second. That's faster than, and Ethernet connections and a whole lot faster than anything you can get down the Internet..
All right, this is the end of my rant. Thank you for listening.

[camerongray]

From what I can see there is no way to do what you are wanting, you would need to get a separate router that has a "WAN" port that you can connect to the Netgear modem.

What are you hoping to gain by using the separate modem?  People tend to replace their ISP provided router with one of their own to get better performance/more features.etc but I can't really see a reason to replace the modem while keeping the ISP's router.

[Dioxyde]

Yes the netgear modem has more channels and I've been told will increase my speeds. Wireless is really faster than wired? I haven't heard that, that's very counter intuitive. Have I gotten bad advice? The thing is the netgear is a modem only so it will not provide wireless, I've heard separate modem and router setups are ideal, so I guess I was wondering if I could use the netgear as the modem, wired to my computer, and the xfinity as a router for wireless. Am I on the wrong path here?

EDIT: And yes the motivation is to get higher speeds, mine are pretty lackluster for what I pay for.

[camerongray]

I'd be surprised if the new modem gave higher speeds than the one that is designed for your ISP.  If your speeds are low then you would be best to talk to your ISP about it to see what sort of speed you should be getting on your current plan.

If you've already opened the modem (I.e. you can't just return it) then you may as well try connecting it directly to your PC with a cable and run a speed test to see if it does give any speed improvement vs plugging directly into the current router. If there is no improvement then there isn't really any point in investigating further.

As far as wireless being faster than wired. Ignore what Geek said there, in almost all cases, a wired connection will be faster and more reliable than a wireless one.  Besides, your wireless access point/router is connected to the rest of your network with a wired connection!  In particular, your current router can do up to 1000mbps over a wired connection but can only do up to 300mbps over wireless.

[Geek-9pm]

In my own defense.  
The modem/router that Comcast provides does 150 Mbps on  local wireless. It does gigabit on local wired.
However, older Ethernet stops at 100 Mbps. My old wired stuff does not do over 100 Mbps, so I get high transfer speed if I use the wireless instead. My wireless adapters are newer.

Important. Speed in NOT cumulative. You do not increase speed by putting devices in a daisy chain.  Adding a gigabit router to a 50 Mbps modem does not do anything to increase internet speed.


About Comcast:

Comcast today announced it is increasing the speed of its popular Blast! tier by almost 50 percent to 150 Mbps (formerly 105 Mbps) and introducing a new Performance Pro speed tier of 75 Mbps.Jul 7, 2015

That was last year. Still, many users get nowhere near that speed munless they pay a premium price.

Also, there are other factors that degrade speed. Such as having too many people son the network all at the same time watching movies or doing massive downloads. The worst thing is doing bit torments, which suck your bandwidth. I had to block one of my family members from my internet connection because he just did not get it. I warned him. . Bot Torrents suck.
If you have a speed problem, consult with your provider. I have found Comcast to be reasonable most of the time.