Framerate issues on a good system

Specs:
i7 6700HQ
16GB RAM
GTX1070
OS: Win10

I get good framerate in small, medium and pretty large game. However, when the game becomes really hectic my framerate drops in the <1fps. I thought it was a natural thing, but yesterday I was informed it wasn't.

What I tried:
Checked network connection; no issues there.
Checked if the game ran on the 1070; it does.
Checked CPU workload during runtime; 27% although thread 8 is at 90-100%
Checked CPU and GPU temp; everything is nominal.

It would be very appreciated if you could help me get this running optimally, I really enjoy huge game and it would be awesome to do so in a acceptable framerate.

This is the battle
http://zero-k.info/Battles/Detail/446986
I was informed by 2 player that they were not lagging. During this battle, lag was so bad I was 40sec behind at time.

Are you using a stock configuration? Or are you maybe using some laggy widgets?

If the game is lagging again, enter /debug and make a screenshot. It'll show what exactly is causing the lag.

Sadly your 1070 is not going to be better than a 750 ti in this game.

PS: I'm playing zk on a 3.2 ghz laptop and don't remember lagging out in any serious game so it really shouldn't happen for you.

quote: Sadly your 1070 is not going to be better than a 750 ti in this game.

I play almost perfectly fine on GeForce 8500GT :D (full hd, windowed, minimal everything)
it's 10 year old
a slightly better(something mid from ~2010 year or so) 256-512mb is all zk can take afaik

Weird, I have a very good connection. Maybe it's the latency because i'm in North America and most players seem to be from Europe?

To check if it's connection/lag just watch the replay.
If you have low fps in replay as well - it's not connection.