Hi I need advice. I have a 1GB internet plan with my ISP. Router is an Asus AX6000 WiFi 6 (RT-AX88U). With my 8 Nest cameras, two Nest thermostats, and many connected devices/phones/ipads/computers - my internet is now incredibly slow. Looking for recommendations on what I can do. 1GB is the maximum speed offered in my zip code. Wondering if I should go to a Mesh system? Would a NetGear Orbi WiFi 6e help? House has three stories, each being the same square footage. Total is ~2,400 square ft (with lots of concrete and steel). Thanks for any recommendations.
Is it 1G over cable? If so what is your upload speed? I suspect probably 50 megs or so?
If all your cameras are streaming, even at low quality, it could be saturating your upload, which will severely impact your download (TCP is two way, downloads need to send acknowledgements in the upload direction, etc). Check the utilization in the router on the upload and see if you are at or near your limit. Start with a baseline test with a wired PC plugged directly into the ISP device to see your full speed, advertised as 50 doesn't mean you actually get 50.
If that isn't the issue, it is likely that it isn't the number of devices or even how much bandwidth those devices are consuming. Many modern devices put out a ton of garbage broadcast, MDNS, multicast, heartbeat, etc traffic. Much of that traffic has to be processed by the router CPU. The more devices you have that do this, the more the compounding effect. One device sends a discovery, the other 30 respond, and the router has to process all of that. Multiply that by 30 devices doing it regularly and you end up with a bogged down CPU.
From what I've seen, Windows PCs generate the least amount of this traffic (though it has gotten worse over time especially win 10 and 11). Android can be a bit worse depending how many android devices you have. Apple devices (PCs, Phones, Tablets) are worse, but still manageable to an extent. There have been several reports of various home hubs misbehaving and sending out way too much discovery traffic. Then the various cheap chinese IOT devices are by far the worst. Basically these companies are taking a camera, light bulb, TV, whatever and slapping a cheap wifi chipset and OS on it as an afterthought.
Sometimes segmenting these devices can help reduce the "snowball effect" some but each scenario is different. Some with many IOT devices will set up two or more routers to spread that load out and create full isolation. One dedicated for IOT stuff, sometimes even with multiple guest networks with isolation, then the other for your "normal" stuff. From a security perspective this makes sense with those IOT devices (many of which have been caught doing stuff they shouldn't be, like Wyze cams talking to Chinese Military servers etc).
If your wired speeds were fine with wireless devices connected then it would just be a matter of looking at wireless settings and tweaking stuff, but the fact that wired is suffering until you disconnect wireless devices tells me it is something overloading the CPU on the router or your upload speed, and not necessarily number of devices or download speed.
If that is the case your options are to try and spread the load out amongst several routers (your main/most powerful plugged into the ISP, then one or two more plugged into that for the IOT devices) or some semi-pro higher powered devices.
You might be able to alleviate it somewhat by tweaking multicast settings on the wifi advanced, but you'll sacrifice performance of the cameras and IOT stuff in exchange for helping your regular stuff, which may or may not be ok.
You can try adding just one wireless device (or one type, like all your cams) at a time and see when your wired performance takes a hit. Maybe there is one particular device that is causing the most issue then you can focus on that one.