Lag spikes in raid

Can someone tell me please what the heck can cause that?
i have no latency issues outside raid instances, but once too many things happen in a 25 man, lag gets up to 2k ms. Its the same with optimize net speed option on or off.

Edit: never had something like that before 4.1

Today: it jumps to 2k when we pop hero, than it goes down to extremely low ms, what i didnt see before, sometimes 10ms and so. And staying ok after even after popping heroism, wich is an usual lag fest

I am experiencing more or less exactly the same issues, was in a troll hc just before the raid Im in now and no lag at all, with lots going in a raid environment Im getting lag. Im from the UK on Virgin Media ISP if that helps.

Go into the new network options in the options tab, that has not quite fixed it for me but its made it a lot better. Im still having more latency than usual but not more 2-3s spikes.

Sorry, unclick configure network for speed or whatever it is in there^^.

FAIL (the browser should render some flash content, not this).

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