It seems if you join a (large) group, for example 20 people, your dps drops quite a lot. It happens everywhere, not only in Cyrodiil.
It doesn't matter if you're in a crowded area or just pure solo somewhere, as long as the healthbars from the 20 other people are showing, your fps is affected.
If you leave the large group, the fps increases right away. I'm not sure if it is the healthbar overlay that causes this, or it has a different reason.
Edited by Excaltic on May 3, 2017 2:21PM