Internet speed goes down to 100 Mbps when you start using it, but this isn't always true.

F5F Stay Refreshed Power Users Networks Internet speed goes down to 100 Mbps when you start using it, but this isn't always true.

Internet speed goes down to 100 Mbps when you start using it, but this isn't always true.

Internet speed goes down to 100 Mbps when you start using it, but this isn't always true.

Z

ZenYcca
Member

61

09-04-2026, 03:39 PM

#1

I've got a home internet speed of 500/250 Mbps with my router and Windows 11 installed on my PC. The issue is that when I turn my computer off and back on, the internet drops down to just 100 Mbps. If I unplug the ethernet cable, it goes back up to gigabit speeds. This only happens sometimes; it never happened before with Kubuntu. Device Manager shows everything is fine, but speed tests show a drop at startup. I've tried some tweaks and even bought a new Cat6 cable, but nothing works. My motherboard is B550-plus and the network card is a Realtek PCIe 2.5 GbE Family controller. In Device Manager, I checked "Speed & Duplex" and also looked at "Wake on" settings, but that didn't help either. What could be causing this? Is there a fix?

Z

ZenYcca

09-04-2026, 03:39 PM #1

I've got a home internet speed of 500/250 Mbps with my router and Windows 11 installed on my PC. The issue is that when I turn my computer off and back on, the internet drops down to just 100 Mbps. If I unplug the ethernet cable, it goes back up to gigabit speeds. This only happens sometimes; it never happened before with Kubuntu. Device Manager shows everything is fine, but speed tests show a drop at startup. I've tried some tweaks and even bought a new Cat6 cable, but nothing works. My motherboard is B550-plus and the network card is a Realtek PCIe 2.5 GbE Family controller. In Device Manager, I checked "Speed & Duplex" and also looked at "Wake on" settings, but that didn't help either. What could be causing this? Is there a fix?