FTTH 1gbps not getting full speed on 1 PC out of 2

[jack.spw]

Hi i have 2 computers one of them i use as a gaming PC and the other one i use as a home server(old gaming PC) and i am not getting full WAN speed on the home server on https://www.speedtest.net but on the gaming PC i am getting full speed. Both have gigabit LAN adapters and the router is gigabit. The file transfer between the 2 PC's locally happens at 100MB/s.

Local File Transfer
The speed tests where done with nothing running on it only speedtest.net
Gaming PC Speedtest
Server PC Speedtest

Home server specs
Gaming PC specs

I have tried safe mode and changed cable and port
Problem on both PCIe and on-board LAN card.
what can i do to speed up the home server?

 

[jack.spw]

NVM found the answer CPU is to slow i guess. while doing speed test CPU touching 90%@600mbps in task manger for download but for upload 50%@900mbps.

 

[Tesla-Coil]

Due to the CPU.

Cheers