How to diagnose home internet speed issues

[boss281]

I have Comcast/Xfinity and a 1GB Gateway for internet access and streaming to the TV.

I have 3 laptops in the house of varying ages (none really THAT old), all in Windows 10, all with latest updates. Two have identical wifi network adapters (Intel Dual-band AC 3165 and latest Intel drivers (19.51.29.1). Both of these usually have a network adapter status of full signal (all bars) and 390-433 Mbps to the adapter, sometimes a bit lower. The newer of the 3 machines, has a Killer WiFi 6 AX1650w 160Mhz wifi adapter with Intel 21.90.2.1 and has a status of 833Mbps consistently. On paper all blazing fast.

The laptop with the Killer Wifi Adapter always displays SpeedTest or similar measuring tool speeds of 550-620Mbps. Cranking fast.

Ethernet connections confirm the speed to the Gateway through coax is as advertised. If I had a wired network we'd all be very happy.

BUT:

The other two machines (Dell Inspiron 5770 and Inspiron 5567) NEVER have speeds over 200Mbps (which is rare anyhow), and USUALLY exhibit speeds in the 25-50Mbps range. Sometimes 10-15Mbps. When this happens I always check the fast machine. Still fast. And my android phone is very fast too.

All 3 laptops, oddly, have fast upload speeds measured around 39-42Mbps. That shows me the signal is strong and at least perform uploads similarly.

So I'm curious: why is one machine always really really fast, and the other two always much slower? How do I even begin to diagnose this?

Or, is this a normal thing?

Note we are an older couple, no others in the house, and the only other internet use is a camera hub (Arlo, which is almost always OFF except at night).

Thanks.

 

[Bighorn]

I use Speedtest.net by Ookla, Wireless DSL as provided by my ISP, paying for 25Mbps and getting 21Mbps sometimes 26Mbps. I do see speed differences on Wi-Fi connection to my Router in one Notebook because the Router is providing 802.11n service but that particular Notebook has an 802.11ac adapter, all the other Wi-Fi connections are 802.11n plus a few Gigabit Ethernet-connected Desktops. All that to say there are variables, both with LAN/Local Area Network [in the house] and the WAN/Wide Area Network [or Internet]. We have little to no control of the WAN, just from the Router/Modem in.

 

[boss281]

That's just it. The external WAN seems to be getting delivered fine to the Gateway, and from the Gateway to the 3 laptops the Adapter Status function is indicating 390-433Mpbs coming to the laptop. One machine will return blazing fast times DL and UL times (on SpeedTest), the other two both have fast uploads but lethargic downloads. I understand the HW is different but the indicated Status is telling me I should consistently get at least HALF that 400mbps or so speed indicated at the laptop adapter. Or am I not understanding something?

 

[Tim Locke]

The adapters make a difference. The tolerance on the random interval before a blocked transmission is retried makes a difference. The small number of channels available on 2.4Ghz for n or g doesn't help. The ac adapter is always on 5Ghz I think you can force n onto 5Ghz but then the layout of your house will make more of a difference.

Although nowadays Wifi works very easily and , unlike earlier days, sets up easily it is still a complicated thing inside.