HELP FROM YOU GUYS WOULD BE MASSIVELY APPRECIATED! =)
So glad I have come across this thread.
I am having a very similar issue.
I have bought quite a high spec laptop (i7 4700 MQ 2.4GHz, 16GB RAM). It has 2 video cards - an integrated intel one, and nvidia 700M. nvidia driver updated. Playing the game at LOW settings (even though its suggested extreme)
Starting the game is ok FPS, but once more units start being made after about 5 minutes, FPS starts to drops massively.
It's weird, because there are some intermittent moments when the FPS will suddenly become perfect, even deep in battle with high demanding graphics. These moments will last for around 20-30 seconds (I noticed that during these moments, the laptop's fan is quite loud), and then it will suddenly revert back to constant awful FPS. I haven't formally measured it, but we're talking 2 or 3 frames per second in the late game.
As someone mentioned above, I am quite convinced that it is using my darned intel integrated video card, rather than my nVidia. But I have no idea how to check this, or how to force it to use nvidia.
It's so frustrating as my much lower spec old PC had far superior gameplay compared to this.
I would REALLY appreciate anybody's help or advice, as this is really bringing me down! Unplayable =(
Thanks for reading
