heavy FPS frop in forest and thicket, suggestion

I have extreme drop of frame rate in Dread Thicket and Pools and Streams, other forest areas maybe too but those two are the worst.

I have not played much since introduction of lower quality textures. They are great and when doing some maps I thought they improved my performance a lot. While they did improve it, it turns out this was not the biggest problem my PC had with the game. When I tried farming Dread Thicket my GPU was simply overheating. Most probable reason is too many objects.

I understand you don't want to disable weather effects as they create mood, indeed darkness is pretty cool. This however seems a bit unnecessary:
http://i.imgur.com/jJSwt.jpg
It's nice but most people wouldn't not notice a difference after cutting the number of those bushes in half.

There are similar decorations on Pools and other forests. When looking at Pools and Streams I also noticed there are ants walking on ground. After clearing the area many times I have noticed them for the first time! It's nice, I'll keep it when playing on better machine, but I'd like turn it off on my weaker PC. I don't know how much resources they need but surely it's more than 0.

This should not be difficult to implement too - just flag half or most of the bushes and make client not show them. It is probably less work than recent texture quality change, might be less noticeable and make a much bigger difference in performance on weak machines.

My PC is quite old, dual core AMD64, GF9600GT, 2GB RAM. I have no problem when playing on better PC.

I can run almost all areas without any problem. Yesterday I did a map that was too hard for my char: I was running around in reef map, luring easily over 100 monsters of about 10 types doing their different attacks, I was cursing them, phase running and attacking, I kept running near and through water and around shipwrecks. In this map my PC had no problem handling the game, but it chuckles when I enter Pools or Thicket even when fighting single enemies or not fighting at all. No other cave, dungeon, areas with water or flames causes such problems. While I understand my PC is below recommended, doing completely fine fighting hordes of monsters seems like a good indication that I can play the game.

In summary, GGG, please add detail level to graphics option.