Driver - Driver Only (Killer Control Center not Installed).

Operating System - Windows 10 (Power Option set to High Performance).

Ethernet Cables - Amazon Basics RJ45 Cat-6 Ethernet Patch Cables.

Switch - Netgear GS305 5-Port Gigabit Unmanaged Switch.

Cable Modem/Router Combo - Xfinity (Arris) TG1682G.

NIC - Killer E2400 Gigabit Ethernet Controller (Speed & Duplex set to Auto Negotiation (No 1000 Mbps option)).

After the switch (and then going back to a direct connection to my cable modem/router combo, I'm limited to 100Mbps. Before the switch, I got virtually the full speed of my internet plan (250Mbps). Prior to installing the switch, I had an ethernet cable running directly from my cable modem/router combo to my desktop, which never game me issues. I also connected my work laptop to the switch. Yesterday I installed a switch between one of my cable modem/router combo ethernet ports and my personal desktop. No way of knowing for sure, but it's been working as designed for hours now with multiple restarts and shut-downs. The reason I am thinking this is because, every time I turn off the PSU and remove the cable, my GPU LEDs reset, but only when power is completely removed from the motherboard, not when the computer is simply shut off. I'm thinking that fully removing power from the motherboard and allowing any components to deenergize allowed the NIC to reset per se. Between originally installing the switch (when this problem first occurred) and step 4 above, I never turned off my PSU (the actual switch on the PSU, not just turning the computer off) / disconnected the power cable. keep reading: Moved computer back up to original location, connected to switch using all the same cables from before today (aside from the RJ45 connecter I changed).

You're probably thinking it was the cable.

Temporarily relocated computer down to cable modem/router combo and connected to existing port on cable modem/router combo with different cable. wireless network achieves internet plan speeds (250Mbps), wired network now reads 'Brett', wired network STILL limited at 100Mbps. Replaced RJ45 connector on cable from cable modem/router on end closest to computer. These are the things I did today, in order: However, m y computer is back up and running with a 1.0 Gbps connection and identifies instantaneously.

If that doesn’t solve the problem and you have an empty PCIe slot, just get an Intel-based gigabit NIC instead.

I’d suggest you bite the bullet, uninstall the current drivers and install the latest full driver package (including KCC) from the Killer website, then test again. Killer uses different chipset manufacturers for different generations of their adapters. Killer E2400 is based off of a Qualcomm Atheros chipset.

Killer e2400 gigabit ethernet