AC3 Lag on gaming pc :(

Just bought a retail copy of ACIII and it lags like hell in certain areas like in Boston etc. Is there any fix for this bug?
Just bought a new Cpu and mobo today and ACIII is lagging. Btw Battlefield 3 MP plays well above in 65-70fps on ultra.
 
Solution
Assassin's Creed 3 has some optimization issues in the cities, especially if you were on an AMD or pre-Sandy Bridge Intel CPU. The game leans very heavily on a single core and lets the rest sit idle, so you're probably hitting a CPU bottleneck. To improve performance, you can try overclocking, that might help a bit, otherwise all you can really do is turn down the environment details, that will take some load off the CPU and improve performance a little bit.
Assassin's Creed 3 has some optimization issues in the cities, especially if you were on an AMD or pre-Sandy Bridge Intel CPU. The game leans very heavily on a single core and lets the rest sit idle, so you're probably hitting a CPU bottleneck. To improve performance, you can try overclocking, that might help a bit, otherwise all you can really do is turn down the environment details, that will take some load off the CPU and improve performance a little bit.
 
Solution


How can a newer cpu like fx 6300 bottleneck? Btw my Specs are in my siggy, I am just getting 10fps more than what I used to get on an Athlon II X2 260
 
The FX 6300 isn't really new, it came out in 2012, and has rather poor single core performance, AMD chose to sacrifice that aspect as part of the 2011 Bulldozer design in order to push higher clock rates and cram more cores onto the CPU with the hope that developers would adapt their software to be more multithreaded in the future. 2012's Piledriver improved single threaded performance somewhat, but AMD's single core performance is way behind Intel's and has been for the past 5 years. For games like Assassin's Creed 3, which heavily rely on one CPU core, that leads to poor performance. In single threaded applications, your FX 6300 isn't that much faster than your old Athlon II. Fortunately most newer titles aren't coded that way, and the FX 6300 will put in a more respectable showing in newer games, though still will get outperformed by similarly priced Intel CPUs.
 


On titles with better multithreading, the FX 6300 will fare better, but still won't beat a quad core Intel CPU like an i5. At best it might slightly edge out the i3s, which are dual core with hyperthreading, though that tends to only happen on games that scale beyond 4 cores, which still aren't that common.
 


Hmm, i5 is pretty highly and insanely overpriced her or else i would have gone with the 4440