Is there correlation between Internet speed and Router's speed?

[blastdarkg]

I'm vacillating between ASUS RT-AC58U (AC1300 enhanced AC performance : 400+867 Mbps)
https://www.asus.com/Networking/RT-AC58U/
and ASUS RT-AC87U (AC2400 ultimate AC performance : 600+1734 Mbps).
https://www.asus.com/Networking/RTAC87U/

Given my Internet speed is 35-40 Mbps do I need 600 Mbps bandwith to take advantage of ASUS RT-AC87U's speed? Will both routers provide same speed at 35-40 Mbps bandwith? Which one has longer range? Is it true that more antennas = longer range?

 

[n0ns3ns3]

the router wi-fi speeds are less relevant. you almost never get them unless sitting next to router without to much wi-fi networks around.
the more advanced models have more capable CPUs that help with better performance related to the number of open connections or multiple devices connected to it.
Also, router is kinda long term investment, today you have those 40Mbps, tomorrow you will get a Gigabit connection. happen to me a month ago, went from ~65Mbps ADSL to a 1Gbps fiber.

 

[kanewolf]

I would recommend you take a look at Smallnetbuilder's article on buying a router -- https://www.smallnetbuilder.com/basics/wireless-basics/33177-how-to-buy-a-wireless-router-2018-edition The AC87U would be right in the sweet spot identified in that article.

 

[BFG-9000]

Router CPU speed can certainly limit internet speeds. This is more of a long-term issue after support is dropped by the manufacturer and you have to go to 3rd party firmware to get continued security updates. See, OEM firmware can do hardware acceleration, while 3rd party runs entirely in software to provide all the extra features, and that puts a far greater load on the router's CPU.

The ASUS RT-AC87U has been known to overheat and lock up for four years now so I wouldn't recommend it. If you want longer range then you should read tests of individual routers at long range, and 2.4GHz is far better than 5GHz for long range. At only 40Mbps, even a 20MHz wide single channel at 2.4GHz would be sufficient so you could consider an inexpensive router in the $40 range for now and upgrade later only when you need it. After all there may be far better routers available a few years from now.

To start, I suggest perusing these router charts to see the relative performance. On each line you can click the router to read its individual review, including how it does at long range.

 

[806chau]

Both WIFI routers will work just fine with 30-40 mbit service. The Advertised speeds are not real life, if curious read those articles provided above. WIFI coverage depends on many other factors, like neighbors' noise, distance, that what kind of walls the signal need to get through which you don't find out until after installation am afraid. If you go wired, you wouldn't have any of these problems.