@woozle Thank you for your precious explanation. I've tried change channels that makes a little more difference. I will take what I can take.

@woozle thank you for response. It was already on USB 3.0 socket but I change to another 3.0. It goes to 400Mbits now. However its still low.

I get only half download speed of what's available. I've checked the connection with ethernet cable. I can take 900-1000mbit however when I use the T4U I can only take 250-300 Mbit. I also tried with...