@amcwit12 

In narrowing down a speed test you want to test speeds on different devices on both wireless bands (2.4GHz/5GHz). Also test at variuos distances, as the environment will give you different speeds.

If you wire a computer into the LAN port of the TP-Link router speeds wont be exact, but they should be close as if you were directly to the modem. If speeds are less then half, a speed very low then swap the cable and also try a different port. If they are still slow use use a different computer as the limitation at timse is the device itself rather then the router.

As far as the router make sure it is running the laetst firmware. You can compare builds by logging into the router and looking at the bottom of the page. Compare that build to our official web page. The build numbers actually refer to dates: Link

@Tony 

I hope it is okay I piggy back this thread. I am having the same issues as well. I recently just upgraded to 1 gigbit internet. When connected to my modems 5Ghz wifi im getting speeds that exceed 500-600mbps. However when connected to my Archer A7's 5Ghz wifi, I am not reaching even close to 20mbps, it has consistently been slow and usually around 17.50mbps at most. I tested this on the 2.4Ghz wifi band for the A7 as well and the speeds are the same at 17.50mbps. I am current on the firmware, I've tried to power cycle the router, I have even gone back to factory settings. After a reboot, speeds would return here and there. However this past week has been the worst. When I initally installed the router a few weeks ago I was getting 250mbps and higher speeds on the A7's 5Ghz wifi, and around 50mbps on the 2.4Ghz wifi. Which was acceptable considering anyu interference around the home.

@Tony I changed my servers to google servers and my router now works a lot better. 8.8.8.8