like you said, I went to safemode with network, the upload speed is always 204mbps.

ookla chrome 88mbps
tmspeedtest chrome 301mbps

ookla chromium 90mbps,
tmspeedtest chromium 302mbps

ookla opera 87mbps
tmspeedtest opera 302mbps

ALSO I tested my Cat5e cable too, switching ethernet ports with my Cat6 cable, same results.
I did a little bit of googlin and went through regedit, cpu-z validator. I don't have spectre mitigation enabled, It's not even patched cuz I never update my windows  .

should I just give up and call TM to send their technician over? :confused:

Less than 600 including shipping

USB->RJ45 adaptors are not built the same. I will tend to suspect that first. Have you done some internet searches on your particular brand and what speed rate it can achieve?

What router are you using?

He insisted he never update his windows and didn't want to mention his laptop/desktop CPU model stuff.

No further reply from him/her on CPU overheating throttling.
~.~

Oh.....that fiber cable damaged excuse? 

Anyway, currently TM has routing issue.
Windows version?
CPU temperature? (Got a feeling your issue is overheating instead of microcode)

Oh....and someone said he disabled windows update..... 



Disable both spectre and meltdown mitigation via registry and reboot.

To disable mitigations for CVE-2017-5715 (Spectre Variant 2) and CVE-2017-5754 (Meltdown)



Then connect your cable to Lan adapter within laptop : Realtek PCIe GBE Family Controller. REMEMBER TO disable your WIFI. Make sure 'Balanced' power profile is selected and the laptop is powered via main electricity.
Speedtest at TM, InNeT, Extreme Broadband and Macrolynx servers. Report back

something off with your ping..

i would check for packet loss

dude i get 1-3ms on lan... 4-5ms on wifi

so ures seem like router issue if multple devices seeing high ping..
da guide of clicking connect/dc lol.. btw noticed the other day with riz mtu 1492.. cant get dat anymore.. try 1480

Any evidence CPU clock throttling for your own laptop?

72'C when idling with minimum 60'C? 
Dude, you have overheating issue.

Try to use table fan and blast the wind right on the bottom of laptop.
Speedtest and see if you can 'turbo' while monitoring the temperature.

You got upgrade your ethernet port or the wifi card firmware?
Try monitor your task manager when speed testing

Yes, kaspersky is known to slow down LAN transfer by half    Please disable it. I was expecting you to use Windows built-in antivirus in first place.

Next, how about the stuff I asked you to do? Aim a table fan to the bottom of your laptop and try to ensure temperature below 55'C and do a speedtest?
You should be able to reach 780Mbps when the temp is around 55'C.
If so, then you better clean the CPU heatsink, fins, fan + reapplying thermal paste.

looks like your cpu is bottlenecking. Have you ever try the original ethernet port and the result are the same as the adapter one too ?The adapter is rated usb 3.0 ? and did you plug it into usb 3 port ? If your laptop is quiet old already  , try clean some dust inside ur laptop and apply new layer of the thermal paste on it.

Nope. Not related at all.

When was the last time you clean your laptop? 

Example of dirty laptop fan + heatsink fins

-.-

Better don't DIY. You gonna break something for sure.
Idle temperature for 3337U is around 45 - 55'C.

No idea on market price.

Anyway, before you send it to shop, DO BLAST WIND from table fan to the bottom of the laptop and verify if you can get higher speed.