Question Computer only reaching ~30mbps download speed when it used to go up to ~500mbps.

Mar 29, 2021
Wasn't able to stream video for a while as my it kept buffering and at time my computer would stutter when watching it. Noticed that my PC only reaches ~30mbps download, ~10ping, ~10mbps Upload, shown by multiple speed testers and my PC also stutters and even freezes for multiple seconds until the test is done. Just a week ago my computer was reaching ~500mbps download around the same time I was able to stream videos. Used the same ethernet cable connected to my pc on my laptop and my laptop is able to reach ~500mbps download so its likely something to do with my PC. All my drivers seem to up to date.

CPU: i7 9700k
RAM: Corsair Vengeance 32gb
Motherboard: MSI Z390-A Pro
first i'd contact my ISP and see what they have to say.
if no solution through them;

a fresh install of all motherboard drivers.
run drive test(s) with chkdsk. if your drive where temp directories are stored is failing, it can cause issues like this.
test the same system through Wi-Fi and see if speeds improve.
run Memtest to check RAM.

if still no luck;
a total wipe and fresh install of the OS and all latest system drivers.
if that has no affect, i'd start to lean towards the motherboard being the cause of the problem.
Because you report that the PC stutter while download/buffering, I'd take it there is something wrong at your computer.

Like now, it is impossible to tell if it's hardware or software related. Since a full reinstall of windows can be labor intensive, there are a better solution (that can rule out software problems at least).

What you can do is to get a Linux distro, download its ISO image file and then make a bootable usb stick out of that (requires extra software for this - Rufus or similar). The ting is - it let you boot straight into desktop without installing the OS (this is because you can test and see if you like a particular system before you decide to install) - in this case you won't install but the sole purpose is to test if your internet connection work normal under Linux.

Since there are a ton of Linux distro out there, I pick one for you and suggest Linux Lite.

This is what you can test using the Linux Lite distro (point 1 and 3 are optional):
  • At the boot, you have an option to test RAM. This will make Memtest to run to check RAM integrity. RAM may just be fine on your system, but when issues occurs, it's always a good idea to rule that out anyway. Since this is a very time consuming task (normal to let it run overnight) this should normally be the last step.
  • When in desktop, run Firefox ; go to and do the speed test from here.
    • If speed is normal/good here, it mean there is a problem with windows, software install or the network card driver.
    • If the speed is still a problem, there is most likely a problem with either the computer hardware. You should now proceed by testing another computer on the same network.
  • Like Memtest in first step, it is also a good idea to check if the storage devices are in good condition. For that, have a look in the main menu, look for "Disks". WHen that is opened, you can select a storage device on left pane, and there is a little drop down button/menu in the app where you should find something like "S.M.A.R.T SELF TEST / benchmark" (I'm not on a OS that have that app right now, so this is just from what I remember right now). From there you should be able to tell if the storage devices are operating fine or not.