引用自 K0NG：

for around two weeks now i see massive drops in download speed, shop loading images in a snails pace and there is no way to fix it.
.

This is the thread with a similar problem. https://psteamcommunity.yuanyoumao.com/discussions/forum/1/601913886223964743/

I found some solutions and people said the third item seems helpful.

引用自 Barrows：

1. Flush DNS cache:

1. Exit from Steam
   
2. Open Command Prompt as Administrator: Click the Start button, type cmd,
   then right-click on "Command Prompt" and select "Run as administrator";
   
3. Enter the command: In the Command Prompt window,
   type ipconfig/flushdns and press Enter;
   
4. Confirm success: You will see a message confirming that the DNS Resolver Cache
   was successfully flushed.

2. Try to change the download region in settings (Steam > Settings > Downloads);

3. Repair Steam service:

1. Exit from Steam;
   
2. Open Command Prompt as Administrator: Click the Start button, type cmd,
   then right-click on "Command Prompt" and select "Run as administrator";
   
3. Enter the command: In the "Run" dialog box, type the following command (I assume
   that's the the path you used to find the logs):
   "C:\Program Files (x86)\Steam\bin\SteamService.exe" /repair
   
4. Run the command: Press Enter or click OK.

4. Changing the Comcast DNS server to Google Public DNS/Cloudflare DNS:

1. Exit Steam;
   
2. Open Settings: Press the Windows key + I or right-click the Start button and
   select Settings;
   
3. Navigate to Network Settings: Go to Network & internet;
   
4. Select Your Connection: Choose the network adapter you're using (Wi-Fi or
   Ethernet);
   
5. Go to Properties: Click on Hardware properties or View additional properties;
   
6. Edit DNS Settings: Scroll to DNS server assignment and click the Edit button;
   
7. Choose Manual: Select Manual from the drop-down menu;
   
8. Enable IPv4: Turn on the IPv4 toggle switch;
   
9. Enter Public DNS Addresses: Input the desired public DNS server addresses
   into the Preferred DNS and Alternate DNS fields
   Google Public DNS: 8.8.8.8 (primary) and 8.8.4.4 (secondary)
   Cloudflare DNS: 1.1.1.1 and 1.0.0.1 (optional)
   
10. Save Changes: Click the Save button to apply your new DNS settings.

Good luck!

Thank you for your comment.
flushing DNS caches is not doing much for me since i installed Linux and Windows across three PCs with no DNS cache to flush after the clean install.
i went from cloudflare DNS to Google, my ISP and back.

the download speed is fine at night and in the early morning but over the day it drops to unuseable territories. (it was slightly better today but still far away from normal)
between 22:30 and 11:00 it is fine and basically full speed.
between 11 and 22:30 it is unuseable with both ISPs while every other download from every source is completely fine and at full speed.

i currently run Arch with just steam and it still behaves the same.

Testw-arg.tt

Change download region to somewhere where it is "at night" or "early morning."

i tried a lot of countries. entire europe, asia, americas.
right now it is 10:26 and i have 114MB/s Download Speed through steam.
at around 11 it throttles to ~20-25MB/s until 22:30.

but i have an update:
i asked a friend that lives around a kilometer away and he has the same issue.

OP should check windows resource, you can DL if drices is 100% busy, then DL will go Down, work as intended.

Steam use write on the fly with uncompressing data. so CPU amd disk drive performance matters. ( there is 1000 if not 100.000 steam post with this.

So many steam user think its a raw data DL it is not. and that is why other client seem better.
every time check slow download on my pc, my drive work at 100%

i know that a slow HDD or old CPUs struggle with decrypting/unpacking the downloads.
i have a 9950X3D and WD SN8100 (one of the fastest SSDs on the planet)
this is not a hardware bottleneck, it's exclusively a steam server problem as soon as it's not a low traffic time like monday at 4 AM.

引用自 K0NG：

i tried a lot of countries. entire europe, asia, americas.
right now it is 10:26 and i have 114MB/s Download Speed through steam.
at around 11 it throttles to ~20-25MB/s until 22:30.

but i have an update:
i asked a friend that lives around a kilometer away and he has the same issue.

net neutrality/peering issue.

Ask your ISP to stop throttling Steam

引用自 K0NG：

i know that a slow HDD or old CPUs struggle with decrypting/unpacking the downloads.
i have a 9950X3D and WD SN8100 (one of the fastest SSDs on the planet)
this is not a ressource thing, it's exclusively a steam server problem as soon as it's not a low traffic time like monday at 4 AM.

Then it's the ISP between you, steam is in a datacenter, most dont even dara say they are slow there.

but you never know if something is up, you can try ask them but sae as try blaim them for delivery in 12 lane highway, most will accpet this, but as i said so rare we are right and they have a missconfigurated inteface or failed hardware, but yes it can happend.

see even Ettanin suspect ISP throttle or congested network at ISP side.

shame there is no steam event sale then we have point this in top of this.

most notice this then many steam usre DL same time ( aka black firday ) and yes its congested network.

Other issue ( bad packets test )
https://packetlosstest.com/#:~:text=This%20site%20uses%20cutting-edge%20WebRTC%20technology%20to%20check,using%20this%20easy%20way%20to%20test%20for%20them.

even this can happend, its rare but well know among IT network dudes.

ISP side is your ISP and there partners partner into steam and back from them make sure your ISP get the info someone along the line has a issue.

Some ISP think they are not responsible yes they are you are not custommer at other isp they work with, they need to work together or there will not be a internet,

Many know this, but we have seen some ISP try dodge the investigating anything or already know the issue and dont tell anything about it.

Maybe not the nicest way to explan it, but other pc user have seen such side before.
not all ISP is likw that, because what can they do then its another partners problem to fix it. they can only contact them and that is it.

Also why i explan this like that, ( as gamers use to say it fix the crappy network, do not use my words, but we know what i mean here, as gamers. )

0% Packet loss.

To make it clear. Both ISPs are completely independent from each other.
One is DSL from Telekom the other is Coaxial Cable Internet from Vodafone. they aren't working together, they aren't coming through the same wires, not talking to the same backbones.

we don't need to make is as complicated as possible and should ask about why Steams servers are so terrible.
there are a lot of people complaining about terribly slow and inconsistent downloads for several months now.

引用自 K0NG：

0% Packet loss.

To make it clear. Both ISPs are completely independent from each other.
One is DSL from Telekom the other is Coaxial Cable Internet from Vodafone. they aren't working together, they aren't coming through the same wires, not talking to the same backbones.

we don't need to make is as complicated as possible and should ask about why Steams servers are so terrible.
there are a lot of people complaining about terribly slow and inconsistent downloads for several months now.

You missunderstand work together, they have to or you can kiss this world internet byebye.

It's not a choise they have in will not work with other ISP they hate or not.


As example you need to DL a BIOS from taiwan board server as we did in the old days, you go though alot of each world fiber line, so you see they have no choise in have to work together.

And you are not custommer at other partners partner, you can only conatct own ISP with it.

and steam is not a ISP , so you see you have no choise in contact own ISP and steam and ask are all working as its should.