Slow wifi speeds on 3700-NAS100

[K33]

The modem is a hand-me-down and over a year old and so I probably can't get Netgear's support.  It is on the latest firmware from Comcast.

There are so many posts with the same problem but I could not find one with a solution.

I'm getting only 7-12 Mbps download speeds on 2.4ghz for my laptop and 30 Mbps on 5ghz for my pc when I'm paying for 300.  I have taken the laptop to just a couple feet from modem and still getting the exact same slow speeds so location is not the issue.  Connected to lan cable and I'd get the full 300 speed and so ISP don't seem to be the issue.

I have verfied in the wifi settings that it is set to "up to 300" for speed and have tried channels 1, 6, and 11 and they all produce same results.  I don't know what else to try.

[FURRYe38]

What are your wired speed test results with a wired PC. 

What wireless devices are you using to test speeds? 

[K33]

I don't have a way to test pc to modem via LAN cable.  It's too far.  With the laptop connected via LAN, however, it is 300 Mbps.

Only tested via Laptop and PC.  No mobile devices (phone, tablet, etc) tested. 

[FURRYe38]

Wireless device speeds vary depending upon design, support and configuration. 

[K33]

I have the configuration set to "up to 300 Mbps" but I'm only getting 30 Mbps on my pc and only 7-10 on my laptop.

[FURRYe38]

The up to 300Mbps is a connection rate between the modem and the wireless device, not actial bandwidth speed thrughput. Two different things. 

[K33]

Right but laptop was getting 300 Mbps via wired connection and therefore should still get 300 Mbps via wireless, should it not?

[FURRYe38]

No. wired connections have less over head and less variables that impact performance. Other considerations would be again, wireless device support and design. 

[K33]

That still does not explain why all devices are very slow speeds.  I can understand there will be some lower speeds due to conditions and such.  But not to the point where I'm only getting 5-10 Mbps on the laptop just standing next to the modem or other devices not getting more than 30 Mbps.

Tested on my phone and it's only 5-7 Mbps.