why only download is slow but upload is fast on my computer?

I'm confused about a network problem on my PC. It hasn't had a problem before but suddenly its happening often since a week ago.

I tested the Internet speed at speedtest.net. My environment is:

OS: Windows 10 Pro
Network bandwidth: 100Mbps (LAN not wireless)
Average speed before problem: at least 85Mbps

When you see the screenshot you can see there is no overhead on my network status at testing time in the resource monitor.

But why is the download speed slow?

I've tried several methods to fix it including:

Reboot PC and Switch
Unplug LAN wire then plug back in
Disable/Enable NIC
Update NIC Driver
Configure NIC again (IP, subnet, gateway)

If you have any ideas on how to fix this please let me know.

I also wonder this; I've never tweaked the system or even used a system optimization tool.

the1900

Posted 2016-07-13T00:21:15.020

Reputation: 1

Sounds like a ISP problem, contact your ISP, so they can address it – Ramhound – 2016-07-13T01:19:53.427

Normally ISP providers won,t accept the result of speedtest.net. So before raising your complaint try downloading 10 or more big files simultaneously and calculate the speed, as well as take screen shot also. – vembutech – 2016-07-13T02:49:20.333

Answers

There could be multiple reasons for this. It could be a configuration issue on your computer, it could be a router problem or it could be a network problem with your ISP. You should start by trying the same network with a different computer. If the other computer also has the same speed next step is to try resetting your router or checking router configurations. If that doesn't work you could contact your ISP and have them check their part.

user576053

Posted 2016-07-13T00:21:15.020

Reputation:

yeah I've already tried test same network with different PC, It's normal download speed was 96Mbps, So I have thought my PC's configuration is wrong but I couldn't find. same Subnet, same gateway, same DNS, but different IP. It might be some issues with Windows network parameter even I didn't tweak it. – the1900 – 2016-07-13T06:02:10.857

Did you run this when no other programs were running? You don't have like bittorrent running in the background? Also are you using a normal speed drive and not some super slow drive? These are just some of the issues that could cause this. – None – 2016-07-13T11:40:51.330

It looks that you use cable. Make sure that you plug it properly and it's in good condition. Or you can contact your ISP for further advice and help you solve such problems.

katiesi

Posted 2016-07-13T00:21:15.020

Reputation: 155

well, thanks for your comment but If you were right. How could upload speed is fast? If the cable is bad then Rx/Tx both should be less isn't? – the1900 – 2016-07-13T05:56:32.300

I found the answer. It was the cable.

They were connected by cable type Cat 5E. I'd been thinking what is wrong with this and finally I just tried to change another cable then it solved.

One thing I still couldn't figure out is why upload was faster at that time. If the cable has a problem then It should effected Upload speed too but it wasn't

the1900

Posted 2016-07-13T00:21:15.020

Reputation: 1