Low max wireless speeds MR33

[Revoliño]

I was wondering why my MR33 has a relatively low throughput speed down- and upload when I compare it to my other AP's. 

As the MR33 has a 2x2 antenna aray, I would expect speeds of >500Mbps with my 2x2 devices. Unfortunately I am only seeing speeds between 350 and 380Mbps with no L2 and L3 filtering and other ''special'' features like traffic shaping. I also use only 1 SSID.

I did my tests on my MacBook Pro (negotiated Tx rate 867Mbps, MCS9), my iPhone 11 Pro Max and a Apple TV 4K. The AP located in the same room as the devices, so no interference of walls.

The comparing AP's aren't located in the same room but speeds of 600Mbps are standard. Sure, these AP's are different (4x4 antenna array, produced for high density locations), but as far as I know that wouldn't be a problem in this comparison as my test devices only have a 2x2 antenna array. 

Radio settings of all AP's: 5GHz, channel 100, auto power, 80MHz width.

Am I thinking too simple?

[Nash]

What speeds are the wireless adapters on the devices you're using? 802.11a/b/g/n/ac? If you've got a b or g associated, it's going to slow down the AP for everyone else.

Is the MR33 broadcasting the same SSID as the other APs? If you look at the bottom of that SSID's Access Control, what are the bandwidth rates permitted?

Also, as a matter of good practice, I'd reduce your channel width down from 80 mHz. We typically use 20 mHz, for maximum channels. Makes it one less thing to remember when we're doing high density deployments.

[Revoliño]

Maybe I wasn’t too clear with my story, but my iPhone, MacBook and Apple TV were the only connected devices. All were connected on 802.11ac with a Tx rate of 867Mbps and MCS9.

When I tested the MR33, I’ve shut down the other AP’s to prevent interference. Permitted minimum bandwidth speeds is set to 54Mbps.

Your recommendation regarding the channel width doesn’t apply in my scenario as I am looking for maximum speed.