AC1900 C7000v2 - Slow WiFi speed

[Bschiffer]

I have a AC1900 WiFI Model C7000V2 Combo Modem\Router and getting poor download\upload speeds  Comcast is coming out this pm to "troubleshoot" the problem after of course going through the reset of router and signal refresh, checking Mac address is registered etc etc.  Been through this many times with Comcast and I've configured many modems\routers over the years not a newbie to how this should work. Its been slow and getting worse for the past 2 months.  Looking for suggestions on what else to investigate as the cause of the slow speed?  I have replaced the cable from wall to router with a brand new one.  The wifi amplifier is in basement where cable enters house and is the original one that comcast replaced about 3-4 yrs ago when I had a similar "signal problem".  Cables to my house are underground and to my knowledge are original to the house from 2004.

I have Comcast Internet on my bill listed as "Blast!® Internet Plan, Download speeds: up to 400 Mbps, Upload speeds: up to 10 Mbps"

Via Comcast speed test I am getting 63.8 mbps Download and .4 mbps upload.  I realize being hardwired I should expect to get the advertised speed but via WiFi I understand it will be slower but not expecting it to be this slow. 

The modem is in a bedroom on my second floor about 30ft from bedroom where I am running a iMac Quad core i5 3.4ghz

The speed is about the same when connecting to the 2.4 or 5g signal from the router.

WiFi Spec on the Mac is:

Card Type: AirPort Extreme (0x14E4, 0x16E)

Supported PHY Modes: 802.11 a/b/g/n/ac
Supported Channels: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 36, 40, 44, 48, 52, 56, 60, 64, 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140, 144, 149, 153, 157, 161, 165

Thanks for suggestions and awaiting the comcast answer of "yeah its your modem, its old technology etc"  however, its only 3.5 yrs old kind of expect it to last at least another 2 years before its truly "out of date"

[plemans]

what speeds do you get hardwired? 

Are you testing over 2.4ghz or 5ghz? 2.4ghz is a much slower network and more sensitite to interference. 

5ghz will go faster but hitting 60mbps over 2.4ghz is actually considered pretty great. 

[Bschiffer]

Hi - I moved my iMac to the same room as router.  I am now getting wifi speed of 142 mbps download and .7 mbps upload this is via the 5g connection vs 2.4g.  I do not use 2.4g knowing that it will be slower.

I then Hardwired my iMac to the router (the cable is a 75ft RJ45 cable that a friend made me who owns a small networking business).  Oddly enough I am getting slightly slower download speed at 120mbps  and slightly faster .8 mbps upload speed.  Thinking I got a bad RJ45,

I then changed out two different RJ45 cables (that comcast provided 5ft cable - brand new never used) to see if it was a bad wire to router. 

I got 83.2 mbps download and .7 mbps upload.  Still puzzled....

[plemans]

If you're not getting even full wired speeds, then we need to look at the cable connections info. 

Do you have a screen snip of the modems cable connection and event logs?
(cable connection shows upstream/downstream, snr, etc )

[Bschiffer]

Resolved!  Comcast identified that there was signal noise causing the issue.  When looking at the amplifier in my house it was determined (and I should have thought of this) there was no need for an amplifier\splitter as I dropped all Comcast cable TV service 3 yrs ago thus not needing any of my coax connections in my house execpt the room where the router is connected.  As soon as he bypassed the amplifier\splitter and connected the wire from the street directly to the line to my room with router my speeds nearly tripled for both wifi and hardwired connections.  Now getting wifi speed via the 5G @ 175.1 mbps download and 10.7mbps upload.  Feels like when I went from a 486mghz desktop to my first pentium machine. 

[plemans]

Glad that took care of it!

You can mark it solved so others aren't reading through trying to fix it as well 🙂