Question Computers, Routers, Connections Oh My. Downloading from one computers slows everything!

Feb 11, 2019
Computer A
Computer B
Computer C

Computer A Downloads something
Comp B and C slog with EVERYTHING browsing is borderline impossible and videos don't load
Comp B or C download something
Comp A is just fine.

Upgraded my internet speed because people said it might be that, nada.
resetted router, nada.
Got a crap tone of devices , but I don't think thats the issue here.

Setup is ISP : Optimum 200
1 Router upfront (Crappy Opt one). another router is connected a Linksys WRT 32X. (Had to get two routers, needed one in the back, its where all of our activity is)

Whether wifi or direct connection the slow down happens.

Any ideas?

Connection is this

Modem -> Opt Router -> 32X -> Devices .

What's weird is this just sorta happened out of the blue. and it's ONLY my computer that causes the issues.
What it really SHOULD do is when you transfer on B and C it should kill the traffic on A.

That is just how downloads work. They attempt to use all the possible bandwidth. They keep trying to use it all until they get errors. It then slows down for a tiny amount of time and then tries again. A proper functioning download should use 100% of your bandwidth.

The only way to really fix this is to limit the download rates artificially on the other computer. Best is to set the maximum rates in the download software on the end devices.

You could try QoS but you need a different router to even attempt it. It does not always work great depending on the application you are trying to favor.

Still I would first look at trying to avoid the issue by setting rates in the end devices.
iperf3 can test your lan speeds. I'm guess pc b and c aren't hitting 200Mbs. They might have 100Mbs nics and slow wifi.
You should be able to see this while you are downloading if it's not even close to 200Mbs.

If you swamp your line everything trying to browse or play games will suck.

with some trial and error you can find the bottleneck. I'd suggest logging into the router and checking if there is bandwidth usage info. it might also show what link speed wired clients are at.