Latency issue. Help me figure this out, pls

kakamaru

Honorable
Feb 5, 2013
7
0
10,510
Hey guys. So I do a lot of online gaming, and I've been having this issue lately, despite testing, I can't figure out what's going on.

I'm conected to my modem directly via ethernet, and sometimes, with no daytime pattern, I get really high latency in my games (600ms - 1000ms), and in my games only. Speedtest.net reads under 100ms all day long.
But if I plug a router (be it via cable, or wirelessly) between my PC and my modem, the problem goes away, my latecy goes down to 50-60ms.

I'm a regular computer user, and don't know much about PCs or networking. So, could you please explain to me what's going on? Thank you, and excuse my poor English.