Internet only fast after a router reboot but gradually slows down

[SirCobalt]

I currently have a Linksys WRT1900AC router.I don't know if it is v1 or v2 and I don't know how to check. The speeds on my router are insane after I reboot. I pay for 75mbps and after a router reboot I get 700 mbps which is basically all of it. After let's say 12-24 hours the router will be considerably slow. I would get speeds less than 1 mbps and it is getting pretty annoying.

This is my speed after a reboot:
http://www.speedtest.net/my-result/5482900521

Is there a way I can fix this problem permanently? My router is updated to the latest software. I haven't done a factory reset but will later. I am asking this question just in case the problem still occurs after a reset and see if anybody can help me. Thanks!


EDIT:

After about 15 minutes the download speed already decreased to 35 mbps
http://www.speedtest.net/my-result/5482923271

After 18 hours this is my speed now. It decreased further to 2 mbps.
http://www.speedtest.net/my-result/5484626869

I am so seriously disappointed in this $200 router

 

[Pooneil]

It could be the router is getting over heated and doing a self protecting throttling. All though there is no way to know for sure and it could be there are problems with your internet connection or modem.

BTW always test the internet connection and router performance by connecting with ethernet to eliminate wifi as the issue. If the routeing components are OK, connect to wifi and start trouble shooting there. If the router still slows, then try a direct connection to the modem.

That said, if this is a new router and the problem just started, I'd return it. Try a different router of the same model or a different model. Doing this can eliminate or affirm the router as the problem. You should also still be able to get support from Linksys.