@PaulS1971 

Hey

I am going to be honest here, sorry in advance :)

In short, this is a very common issue and really there is no simple answer to it, i also have a 1GB connection so know your pain!.   Basically, there is ZERO chance of getting anything close to 1gbps over wireless, its simply not possible.. let me explain

WiFi is a contended medium and generally, the accepted practice is on average you will get around 40% of the "connection speed".   Connected speed is what the laptop / phone / tablet and the AP report as the "Wifi Speed", generally this is 433 or 866 Mbps.   With that in mind you are expecting to see speeds around 240 to 480mbps depending on the device..   Its the networking version of your calls manufactures  MPG.. its not what you will really get on the road

For comparison, a cable connection is roughly 95% so a 1GB cable will get around 940mbps on average.

This is simply the nature of the wireless.    You are correct that an AX grade device (x60 x68) would be faster between the nodes so could result in a faster connection further away, however its not going to be massively faster and would also require your devices to have WiFi6 cards to get the maximum out of this. 

• Its your call, if the current connection is stable and speed is not the desired result, then Deco9 will likely work for you.  Just cable in whatever you need at max speeds  
• If you want to spend some money and the other devices support it, go for the Deco x range.  Should be 10/15% faster on average
• If you really want the maximum speeds, you need to leave Deco and look at running cables connected Omada EAP1800 Access Points.   That is the route I went down and WiFi now getting around 520mbps all over the house. .  however its £££

Sadly no quick answer to this mate without spending money and running cable you are not going to get anything near the 1GB connection you are paying for.. its a pain!

@Philbert thanks very much appreciate the reply. I do get that Wi-Fi is never going to get line speed connections. Just thinking that less than 50% is below that what I would hope and if anyone had some ideas to get the most out of it  and if the M9's could be improved upon and then I would make a cost/use decision on that.

My work computer is in the cupboard/ office in my house 2 floors above the main AP so hence the X6x thoughts.

Cheers.

@PaulS1971 

You've got good info and suggestions from @Philbert, I'll add my comments as an owner of Deco M9 Plus set. I have gigabit Internet, too.

1. The Deco speed test shows 742Mbps down and 50 up.

This might be an issue with Deco speed test. Connect laptop to second Ethernet port of Main Deco and run speed test from laptop. If you are getting over 900Mbps, just ignore Deco speedtest. If on laptop you are also getting around 750Mbps, you should check Ethernet cable between Main Deco and modem, or just try different one. 

2. Using Wi-Fi about 2 feet away from the Main Deco I get 300Mpbs/50, less with the satellites.

In my speed tests with Deco M9, I've got the following results. At the distance of 6 feet, which is the right distance to run tests, in plain view with no obstructions, when I hold my smartphone I run speedtest on just right, I could get up to 630Mbps.Once in a while. On a regular day I am happy to see speeds around 400Mbps.

For Satellite Deco which is almost ideally positioned in regard to Main Deco, one floor above, the top speed I ever got was 490Mbps, with average speeds in between 200-300Mbps, and as low as 150Mbps occasionally for who knows what reason. 

I would recommend turning off 2.4GHz on Main Network and running speed test from laptop connected to Main Deco by WiFi. You might get somewhat better speeds.

Same thing for your home office: with 2.4GHz turned off, run speed test on work computer from there and also check quality of WiFi signal on that computer. See How to check the associated/link speed on a wireless client

If you get noticeably faster speeds with 2.4GHz turned off, just keep it off.

3. I wonder if switching to X60/X68s would give better results.

The answer: it depends. Before you do that, read this: How can I find a suitable spot for my Deco? Often proper positioning of Satellite units helps a lot in improving signal and stability, and you should check in Deco app if signal between each Satellite Deco and Main (or other) Deco it is connected to is strong.

Also, if I understood you correctly, your Satellite M9 are all connected wirelessly to Main M9 (or each other). If this is the case, they utilize the M9 feature which is separate 5GHz band for a backhaul. They are what is called tri-band.

X60 is not. Which means, you might actually get stronger signal from X60 to work computer, but lose on overall speed from computer to Internet. 

Also, X60 makes sense if your work computer supports WiFi6. Does it? if it does not, X60 won't deliver much better speed than M9 Plus.

If your computer supports WiFi6, the Deco unit to get instead of M9 would be X90. It is also tri-band. I am reluctant to recommend it, because it is crazy expensive and it is your money, not mine, but X90 is currently top of the line Deco for WiFi6, just like M9 is top of the line Deco for WiFi5. If you'll spend all that money on X90s and still not satisfied, at least you will know that you won't get anything better with TP-Link, and should research different brands of WiFi mesh.

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Side note. If you have TV cable terminating at your office room or in very near proximity to it, you might have an option to deploy Ethernet over TV cable, with proper adapters (google this: MoCA). Which in turn would create possibility of wiring your work computer to Ethernet.

@Alexandre. Many thanks for this all the replies are helpful in understanding regarding my setup to see if I am doing anything incorrectly.

1. With a ethernet connection to the main Deco I get 906/52 for up/down so that's as close to line speed as I am going to get.

2. My test results are pretty much the same. Removing 2.4ghz (annoying IoT bits and Printer don't have 5Ghz) didn't really change anything. My devices show as connected to the 5Ghz band signal strength shows at 75%(-ish) with a SNR or around 40dB.

3. Thanks for this. Yeah I was looking at potential tri-band options hence the potential use of X68's I saw some reference to it helping others.

The household computers don't support Wi-Fi 6 maybe my tablet does so that won't provide any value right now.

Again. Many thanks for the detail you folks have sent. Really useful.