AX86U Pro - why two MU-MIMO options?

[PeterPiper82]

Greetings community! AX-86U Pro owner here. Under the professional WiFi settings menu (5GHz band), I noticed there are two MU-MIMO settings:

1. Multi-User MIMO

2. OFDMA / MU-MIMO

The first one has a simple Enable/Disable toggle.

For the second one, MU-MIMO can only be enabled if OFDMA is also enabled as both are combined under one single drop-down option.

I have some questions:

1. Why are there two MU-MIMO options? Is the first one for WiFi5 (802.11ac) clients and the other one for WiFi6 (802.11ax) clients exclusively?

2. Assuming the answer to the second part of
my first question above is ‘yes’, how
do I enable MU-MIMO (for both WiFi5 and WiFi6 clients) while keeping OFDMA disabled?

 

[SkippyP]

1) I had reached out to Asus a while ago and asked them the same question. According to them - yes, the “multi-user mimo” option is for AC and the “ofdma / 802.11ax mu-mimo” option is for AX.

2) I don’t think you can for AX because as you said (and as Asus also said), ofdma and mu mimo are combined. For AX, mimo can either be OFF or ON (along with ofdma), but it can’t be on without ofdma.

Personally, I think it’s an oversight by Asus. On their wifi 7 routers, they’ve separated ofdma and mimo for wifi 7, so you can control each of those options independently. But those same options are still combined for wifi 6 (AX).

This was Asus’ official response to my question:

The Multi User MIMO setting is strictly for 802.11ac. The OFDMA / 802.11ax MU MIMO setting is strictly for 802.11ax. They are combined for AX because they compliment each other. OFDMA alleviates network congestion with low bandwidth devices while MU MIMO alleviates congestion with high bandwidth devices.

Take that how you will, but the fact that they ARE separate settings in their wifi 7 routers tells me their answer above is not entirely accurate, and points to an oversight as I mentioned earlier.

Personally, I would just keep both settings disabled. In my opinion, neither ofdma nor mu mimo are really beneficial unless you have MANY clients in a very congested network (think hundreds or even thousands of wireless devices like shopping malls, stadiums, offices). For home networks, I think those features are mostly useless.

 

[PeterPiper82]

Hmmm. Ok thanks. I only have a few wireless clients so I guess I’ll just disable both options per your suggestion. I found some other threads on these forums where other people have stated the same thing, that these options are not very useful. Thanks again.