Weird issue with routers

[giwrgosp-]

My connection is 120mbps upload and 120 mbps download. 

On my ISP modem/router, I have connected a xiaomi mi 4a gigabit (via ethernet).

Speedtest results:

 

PC connected to xiaomi router via ethernet-> Starting with 120mbps download, and at about the half part of the download test, it drops to 30mbps. Upload gets only 5mbps.

Laptop connected to xiaomi router via ethernet -> Same results with 15mbps upload.

Phone connected to xiaomi router via wifi (5Ghz)-> Gets full 120mbps up/down.

PC connected to ISP router via ethernet-> Maxing the download speed at 120mbps stable, upload only at 60mbps.

 

Also, transfering files to my phone (phone via wifi to xiaomi router 5ghz and pc connected to xiaomi router via ethernet) reached 500mbps.

How can my ethernet connections be so limited? It just happened about 2 hours... I rebooted every device (ISP router/xiaomi router/pc), i even factory reseted my xiaomi router, and it didnt fix the problem.. QoS is off.

[camieabz]

Suggest you swap around the ethernet cables around to see if the upload speed issues are specific to the PCs / Laptop, and not any of the cables for a start. That removes wiring as a possible problem. Can you try this test too please? 

 

https://www.thinkbroadband.com/speedtest

 

In addition, they have test files for download testing:

https://www.thinkbroadband.com/download

 

N.B. The main test tends to report the median speed, to give a more true real-world indication, rather than a maximum burst speed, so don't worry if it's lower than expected. Also, if not in the UK, there might be a bit of latency, but we're really testing for big differences in start speeds, end speed, and upload speed. You won't need a postcode or provider. Just run it.