Issues With Wifi Adapter

[Pulse]

I know there has been a few of these threads, but I really can't seem to find the answers that I'm looking.

Since I upgraded my WiFi adapter to a TP-Link T4UH V2 I've always felt underwhelmed by it. I have a 300mb BT fibre line which it has never been able to make full use of despite it connecting to the by router with a full signal and normally between 650 and 866Mbps.

During speed test it normally caps out at around 220Mbps, which I also normally find out is the max speed that I can transfer to my NAS which is a WD My Cloud connected directly to the router via a 1Gbps cable.

This gives me roughly 25-27MB/s transfer speed in windows. The odd thing is straight after updating the drivers early today it was achieving twice that at around 50-54MB/s and for the first time ever it hit almost 260Mbps on a speedtest.

But what could be causing such a huge difference in speeds? I found it extremely odd that it is maxing out well short of what I thought it could achieve? Or I am just wrong and this is what I'll have to accept or upgrade again?

 

[Avalon]

It’s wifi... wifi is a convenience for devices that it’s not possible or impractical to connect via a wired connection eg IoT, mobiles and tablets etc. If you want consistent maximum speeds without the variability and latency, use a cable.

 

[WJA96]

WLAN is a very complex system. The first thing to bear in mind is that the speeds claimed are completely theoretical.

The 1200Mbps or 1300Mbps figure is generally achieved by adding the 300Mbps theoretically possible on the 2.4GHz band to the 833mbps theoretically possible on the 5GHz band. These figures then have be halved because the system runs half-duplex. So even under perfect conditions you’ll never see more than 415Mbps transfer speeds.

The system is also runs at the speed of the slowest client connected. This is a common problem. If you have an 802.11b client connected at 11Mbps the whole 2.4GHz band runs at 11Mbps (5.5Mbps half-duplex). On the 5GHz band if you have any 802.11N devices that are connecting at 150Mbps then all the other 5GHz devices will run at 150Mbps (75Mbps half-duplex). The 833Mbps theoretical figure requires all 3 available data chains to be in use. Most 802.11AC devices typically only run 2 chains of data, so instead of getting 833Mbps you get 560Mps (280Mbps half-duplex).

You also state that you see maximum signal strength. I presume this is the signal seen and reported at the client? Just because the WLAN adapter can pick up full signal from the access point doesn’t mean the access point is receiving the signal from the client at the same strength. Another common issue is having the equipment transmitting at too high power. It’s a bit like a rock concert. It’s loud, so the people at the back can hear it, but it can sound distorted for the people right in front of the speakers. So you might find you get better overall performance by turning the transmission power down.

If you can, check the RSSI at the client and access point. They should be balanced. You don’t want one shouting and the other whispering.

And then there is the wireless environment. If you’re lucky and you have no neighbours you can pick a clear channel. That’s unlikely though.

It’s super-important to get a clear channel (or set of channels because the chains are combined across 2-4 bands). So a wireless survey is pretty important to get the optimum speeds. Again, at that rock concert, you can just about hear the person next to you, but it’s mainly drowned out by the noise round about you. Turn off any WLAN devices you don’t need. For speed testing, turn off EVERYTHING except the access point and the client you are testing. It’s surprising what a difference that makes.

WLAN is designed to work under truly appalling conditions. It starts out by trying to be perfect and run at the highest possible speed then slows down as the conditions require so that you still get some signal.

And, just to rule out everything - you have got it plugged into a USB 3.0 port? That’s actually running at USB 3.0?

 

[Pulse]

Very informative, thank you. And yeah it's definitely plugged into a USB 3.0 port as that was one of the first things I checked.

Just strange how right after updating the driver, which eventually was unstable and I had to roll back to windows driver, it was transferring at double it's previous speed.

It may well be what you suggested about the speed set to the slowest device. Which I'm guessing will be our living room TV as that was showing up in the list last night when I was testing it, but even that is connected on the 5Ghz channel and is much closer to the router, but may well be connected at a slower rate.

I'll just live with it. It's more of an annoyance than anything, I transfer things from my phone to the NAS and I'm guessing that is limited by the phones storage as that only achieves around 22MB/s and doesn't seem to vary.

Just considering it says that it's connected at 650-866Mbps, I would have thought it would easily max out my internet connection. My phone does max out the connection at 300-305Mbps but it's a S10+ and connects to the router at the same sort of speeds as the WiFi dongle which is why I felt disappointed with it.