If I alt tab my frames drop for a while

[Darslan]

anytime I alt tab and then tab back in my frames drop to around 15, my game runs fine normally with only 80% cpu/gpu etc usage (I do have a bad pc) but either way the game was fine 6 months ago, if ANYONE has the fix please tell me it is genuinely unplayable because I alt tab ALOT

[moltzer]

Try -windowed -noborder in the launch options.