Question Extremely Slow download speed, but normal upload speed

[gerritS]

Hey all you beautiful people,

I've got a little bit of an issue with my Internet and I'm getting to my wit's end on what could be causing it.

Basically I moved to a new apartment and got a fresh internet contract with the German Telekom over 100 Mbit/s Download and 30 MBit/s Upload speed. Recently in speed tests my download speeds have been clocking in at a gut-wrenching maximum of 5 MBit/s, while the Upload speed is as it should be at around 30 MBit/s.
So far I think I've ruled out the cause being the connection itself (when I open my router's interface it confirms that it's getting 100 MBit/s download/30 MBit/s Upload speed). I've ruled out the problem being the cable, as I've switched to 2 other cables and still had the issue.

So now I'm at the point where I know it's probably some component or piece of software on my PC causing this.
I'm fairly ready to rule out Bitdefender's Firewall/Bitdefender itself as a cause, because I was using it in the old apartment aswell and didn't have any problems there.
But I really don't know what else it could be so I figured I'd turn to this forum. I faintly remember reading somewhere that the channel may be crowded with download and one could somehow switch channels, but I'm not sure about that.

Any other software that may be causing such a drastic drop in speed? Any ideas of solutions to this weird dilemma?

Thanks in advance!

 

[Lutfij]

You can try and check to see if your router is pending any firmware updates. As for your router's output, how are you tethered to the PC? Disable Bitdefender entirely and see if your speeds go up to the advertised package speeds. If you're working with an NIC that's bundled with your motherboard, make sure you're on the latest BIOS version for your motherboard.

What OS are you working with?

 

[bill001g]

I would always test with ethernet just to be sure. Wifi has all kinds of strange issues at times many of which you can't really fix. If is doesn't do it on ethernet then changing wifi setting might make a difference.

I would look for some kind of software that claims to give performance to certain types of data. You find a number of so called "gaming" network software that is bundled with the bloatware on motherboards and video cards. A very common one is cfosspeed but there are a number. Anything like this you want to uninstall. They can't actually affect any traffic outside the machine and if you have a internal issue overloading your bandwidth between processes on the machine that is best fixed with other methods.

What you can also try is get one of the many unix test USB boot images. These run completely from the USB stick and have a web browser preinstalled so you should be able to run the speed test. Problem is this will just confirm it is a software issue with windows it won't tell you how to fix it.

 

[gerritS]

So I've updated my Network Drivers and updated my BIOS to the latest version (it was on a version from 2020, now it's up to date) however my download speeds are still way too low.
I'm always connected via ethernet cable and I'm on Windows 10.

I'll check through my software to see if anything is using blasphemous amounts of bandwidth behind my back. Bitdefender, Razer Cortex, CCleaner and the like. Are there any known pieces of software that may be causing this?

Another interesting factor is that my WiFi download speeds on my phone are higher than my Ethernet download speeds, but also not as high as they should be. Maybe it's time for a new router aswell?

 

[bill001g]

Unlikely it is the router at those low speeds. If you had gigabit internet then sometimes older router have performance issues. Make sure you have your phone on the 5g radio. The 2.4g radio it would be common to get under 50mbps.

Is it possible to remove the router or does the router have a modem of some kind in it. Hooking you pc directly to the modem is the best way to rule out router issues.

Note the software does not use bandwidth it attempt to monitor and limit certain types of traffic. There is so much overhead or maybe the code is written bad that it can limit your rates. It seems to be cpu related but it is unclear exactly why this software has issues. Most times it is not as bad as yours, someone will only get say 200mbps on their gigabit connection. This is more something to pretend that you can make games run better and gamers are stupid and believe in magic.

Maybe try to boot the pc into safe mode with networking that tends to not load any of the garbage on startup.

Do you have another device in your house you can share files over the network. If your router can mount a USB drive that might work also.

With the rates as slow as you see anything is going to be faster. The goal is to see if it is related to internet browser or something. File transfers in house use a different protocols.