Guild Wars 2

Since last week (raid patch?) GW2 started to use too much of my systems ressources.

I normaly have no problem playing the game and watching something on youtube or netflix on my second monitor.
I know Firefox uses more RAM, the longer I use it, but it will go down after I stop it.

For years, that was never a problem. I had dozens of tabs open. No slow down.

Now last week, things changed. Suddenly the game slows down.
I stop firefox, since it was the only major programm running in the background, going up to 1,2GB RAM usage at that time (I only have 8GB right now)

Then I saw GW2, going up to 1,2GB and later up to around 2GB.
I was on the 64bit client. However it did not happen at its release, so it had to be somethign to do with the patch i figure.

The RAM usage won`t go down after I close GW2, keeping it at 70-88%, not like Firefox, which I used to compare it to.

Th PC slows down and only a restart returns it to normal performance.

Edit
The 32bit client works better, it also goes into the 1,8GB range of RAM usage, but it runs smoother and releases the space after closing the game.