Noticed something.. I was moving files on the LAN from a PC with 1Gbit adapter (Intel) to a laptop with 100Mbit (Realtek), through an Asus RT-AC68U Gigabit router; at the same time I was in a game online and noticed a huge latency spike and decided to check, from 50-60ms it went to a steady 700~ or so for most of the transfer duration. Router QoS settings are set to "Gaming".
What's happening here?
1) Shouldn't QoS give priority to the game packets?
2) Even if that wasn't working, the host PC sending the files is only using about 10% of the Gbit link bandwidth, why the huge latency?
Note: host PC is a decent machine with 16GB ram, i5-2500K at 4.3 Ghz running Win10 Pro x64, SSD
Maybe a problem with my motherboard? (possibly related to this https://superuser.com/questions/1126826/high-pitch-squealing-sound-during-disk-load-operations). The mobo is a middle-range Asus ($150) with Z68 chipset.