I have had great luck with the smart people on this forum before, and maybe you can help me figure this out. We just had a Lumos Networks 2 Gbps fiber Internet service installed, and the speeds are incredible - on one computer:
This desktop system is connected via Ethernet to a Zyxel 2 Gbps unmanaged switch, which is, in turn, connected to the 2 Gbps LAN port on a Netgear Orbi RBRE960 router. So far, so good.
However, the speeds on the other computer, which is also hardwired, are pretty different. While the upload speeds are impressive, the download speeds are considerably lower:
This computer is linked to another Zyxel 2 Gbps unmanaged switch connected to the same switch as the computer above. The cable that links the two switches has a coupler linking two Ethernet cables. What do you make of this? If the upload speeds are the same or better, shouldn't the download speeds also be?
Edited for clarity.
First, I'm assuming you're using all 2.5G connections (not 2G which would be bonded 1G in LAG which works differently)?
Try disabling firewall/antivirus on the PC while doing the speed test. If your results are significantly better, your PC just isn't up to the task of 2G throughput. I suspect that is the issue since the download is suffering more than upload (it scans the download much more thoroughly than upload). If that is the issue, you can either buy a new powerful PC, or just print out the speed test result, frame it, and be happy, since you likely do not need anywhere near 2G to a single PC.
If that doesn't help, watch the CPU in the PC during the speedtest, is it hitting 100% even with firewall disabled? If so, again, new PC or just be happy that you have more than enough speed, and your connection can support multiple computers all with a ton of speed at the same time.
You could try a better NIC in the PC, something from Intel (preferably server class) with its own dedicated processor on it. That may alleviate some of the CPU usage for the actual network traffic, but won't help with CPU usage caused by firewall/antivirus. You can see if there is a different firewall program that is more efficient but I doubt you'll find one that is twice as efficient.
If neither of the above, start checking wiring. Especially that RJ45 coupler, if it is some generic one, those are notoriously crappy. You can pick up good true Cat5e or better ones at home depot or from a good brand name off amazon. But also check your other wiring. If you have a laptop, test it at each point, before the coupler, after the coupler, at the final end near the PC, etc. Make sure the cable is not running along side power wires, or get a shielded cable if you have no choice. Distance needs to be about 330 feet or less. Or if no laptop available and you don't feel like moving the desktop around, pick up a long ethernet (CAT5e or better, probably better to go with a good quality 6 or 6E one) and temporarily run it down the hall directly to the main router, then to the main switch, then to where the coupler is, etc.
Daisy chaining switches should have very little impact so that shouldn't be the problem, unless that second switch has an issue or the cable between it and the first switch is no good.
But at these speeds, it is likely you are hitting hardware limitations. They sold you a 300MPH car but in reality there is nowhere you can drive that fast. 2G internet could support a business of 1000 people. So unless you're running a major hosting operation or porn site out of your house, kinda not needed, especially when most of the sites/servers you connect to will throttle you to much lower speeds anyway (except speed test sites).
I'd start with disabling firewall and antivirus for the test, I suspect you'll see significant increase in speed. Then you need to decide if it is worth the cost of a new computer just to see higher numbers.
Of course their speed test server may just be overloaded if there are lots of new customers coming on and testing. I see your first test has a slower upload than your second so it seems somewhat inconsistent. But if both PCs get the same result repeatedly over time then that probably isn't the problem.
If your router supports any sort of port counters to show errors that could help, but I suspect it doesn't. And the unmanaged switches won't either. That could help narrow it down if it is a wiring issue but the steps above will too.
