Yes. It might. Powerline and WiFi won’t get you 800Mbps. First, your router doesn’t support that speed on WiFi, and even if it did, your devices probably don’t support it. You need at least 4x4 MIMO to ever have the chance to hit that speed on WiFi.

Cat 5e is enough, but Cat 6 is recommended as the price difference is not a lot.
Should be firmware issue.
Only can be done by TM.
Thanks for the advice. But strangely not everyone who have the router has the issue. It happens to some but not all.
Yes it should be Cat 5e, but some good crimped Cat 5 cables can support gigabit.

Copper-clad aluminum cables perhaps? 

Change the cable.

I am on 100mbps, awaiting turbo 800mbps.

TM chat told me possible to downgrade to 100mbps @ RM129 with 2 years contract.

has anyone done this?

I don't need 800mbps.... I checked the data stream, peak usage with 4 persons youtube only maximum 40-50mbps. Never hit 100mbps. 800mbps will be very wasteful

Do you find 800mbps useful ? besides faster torrent and game updates?

Hi, any idea why my UNIFI speed only reaches about 90-100Mbps during speedtest  which was done using CAT 5e LAN wire directly connected to my laptop, although supposedly I have been upgraded to 500Mbps. My router is D-Link DIR-615 which should be able to support up to 1000Mbps using LAN. Tried speedtest many times, but max speed still below 100Mbps. Thanks in advance.

Tell him that Cat5e can go to 10Gbit. With some luck and planning.

What problem? It is performing the way it is designed. Don't mess with things you don't know about. LAN1 port on the BTU is for TM Unifi use, and LAN2 port is for Maxis use. The BTU is not a switch where you can utilize all ports. It is a modem and needs advanced configuration for each ports to be functional.
Just use Cat 5e if it is serving your needs well

Yes, it can. You have to see the specifications of the wireless adapter that you are planning to buy. Make sure it supports 5GHz and AC. Please refer to 1st page green text to see list of wireless adapters. I recommend TP-Link wireless adapters.
It is not gigabit? Could be cable or driver issue.

That’s quite pricey. I would suggest just laying one cable or two cable to areas where you need wireless connection and getting your own WAP. Laying more cables are unnecessary unless your devices can be utilise the cables.

100ish meter is considered the maximum already, and maybe as you say, Belden cables.

Just got my unifi turboed today from 100Mbps to 800Mbps. However after checked speed test through router page (tp link archer c3150) only got around 526Mbps. Router checked support speed. Not sure what is the problem.

Is yours the 500mbps package? TQ

Lol good choice 

guys, is it possible to downgrade from 800mbps plan to 500mbps or 300mbps?

My sweet spot is about 300mbps. 800mbps is really overkill

Labour cost most probably. It is definitely not that expensive.