Assassins Creed 4: Black Flag is lagging. Help?

I just bought AC4 yesterday and it lags like all hell. I tried lowering the graphics and everything, still tons of lag. I don't know what to do anymore. I played Assassins Creed III on my PC and I'm sure AC4 runs on the same engine, so why so much lag? If anyone can help me with these lag problems I will be very grateful.

(P.S. I did not install any patches for the game, so if you think a patch will help, then I will install one)

I forgot I did not have my system specs in my signature. Sorry!

Intel Core i5-310M CPU @ 2.50GHz

NVIDIA Geforce GT 630M 1GB

It is a laptop, an Acer Aspire (Don't remember the exact model name, sorry :()

I am not much help on this without seeing it, but according to videos and forums I have been reading for your issue.

Everyone is using driver update 331.58. I am not sure, which you are on. Also looks like with 720p they were getting 25fps with textures on high and everything else off.

I updated my drivers, which DID help a bit, but still I'm getting alot of lag and its making the game unenjoyable for me. Any other advice on getting higher fps?

Assasins Creed 4 mobile gpu benchmarks

There is not much you can actually do . Your Gpu is low end and AC BF is quite demanding and according to benchmarks you can only play around 25-30fps at the lowest settings at 1024x768 ( maybe if you overclock your gpu you might maintain a minimum frame rate of over 20fps that would make it barely playable )