20MHz for 2.4GHz is narrow band you can only reach max about 50-75Mbps on speedtest if you choose this setting.

Increase it to 40MHz you'll probably get max 125Mbps if you have a supported wifi client/device that supports it. Most newer equipment nowadays already support this unless you have very old outdated stuff at home that'll need Wi-Fi connectivity.

Then there's 2x2 MIMO on top of the 40MHz 2.4GHz Wifi which claims to oduble the speed with 2 parallel antennas.

Do remember that even though your router/AP supports newer technologies such as 2.4GHz wide band Wifi and MIMO 2x2, you need a client that matches it as well.

For 300Mbps plans above, it's recommended that you use 5GHz WiFi instead to gain the extra bandwidth and take advantage of the speed.
For 100Mbps plans below, 40MHz 2.4GHz will be good enough for most people.

My stock router at home is capable of AC1200, it makes sense to get a AC1200 rated wifi adapter or a matching capable device to take advantage of the speed which is 1.2Gbps via wireless.

Do note that speeds are theoretical speeds, give or take 20% overhead with published speeds on the tech sheet, that's what'll get in real time conditions.

With the overheads involved, AC1200 should get you connected at around 867Mbps. AC1200 Wireless cards/adapters are priced affordably too.
That's good enough to cover TM 800Mbps , 500Mbps and 300Mbps plans.

If there are other isps offering 1Gbps plan above, you need to find better routers or don't forget higher end wireless adapters/cards such as AC1900, AX3000 or better to attain such speeds.

AC1200 should be enough for now to cover upto 800Mbps wirelessly for ISP plans in Malaysia for time being.

What is the connected speed for your wireless client? You can look it up under connected Wi-Fi status of your OS.
If it's 867Mbps or so and you are still getting very slow speed on your local based speed tests it means your ISP is at fault.

AC1750 router is good but it's hard to find matching AC1750 wireless adapters out there. Even it there is, you'll be paying a very high price for them while they're rare.

This post has been edited by Candy12: Mar 9 2020, 09:40 PM