Lag spikes

I assume you mean you're getting framedrops. Lag refers to connection issues.

You can get a framerate boost by disabling the Origin in-game overlay.

Hi thanks for the reply, yes sorry frame rate drops. I already have the Origin in-game overlay disabled.

You may want to download/run a program like Speedfan to monitor your temps while playing the game.  It stresses the GPU and CPU a good bit, with 100% cpu load in many areas.  You may have one of two issues because of this, first is temp getting high and thus your CPU processor throttling down to prevent cooking and thus you would get a lag spike.  Second would be a background process eating CPU power that the game needs to run...yeah, the programmers didn't get the optimazation right...and thus you would get lag spikes.  Since it started after a month of playing, I am thinking heat as best option, but with this game, no telling.

Hi Thanks for your reply.

I loaded up speed fan and task manager before booting the game, the temperatures are all fine it does however seem that my CPU usage goes to 100%, even when sitting in the main menu.

I did a bit of searching and found this http://answers.ea.com/t5/Dragon-Age-Inquisition/Patch-made-performance-MUCH-worse/m-p/4101401#U4101401. So seems like it is quite a common problem with the patch.