update your drivers, open d3prefs.txt in documents\diablo iii\ and change DisableTrilinearFiltering to 1, also you can try lowering HardwareClass (1 or 0 is lowest, 6 is highest, id recommend 2 if its higher than that), google core parking and get an app that will unpark your cores, watch those temps, if you're overheating then the gpu/cpu will not reach full turbo modes, also try lowering sound channels, you should be getting higher frame rates than that
This happens to me when i use certain skills and items. Just for giggles, try a different build to see if thats the issue. Another thing that can lag me bad is using a resolution that I'm not using as my desktop. Example. desktop is set to 1600x1024.. If I run D3 at any other rate ill lag. Lastly, you mentioned a laptop, if you are in fact using the wifi, that could very well be a huge part of your lag. Wifi and D3 don't work well together. Try running a rj45 directly to the lappy see if that helps.
As mentioned there are a few apps out there that are supposed to help. Blizz blues actually mentioned one the other day that does similar things that Entro mentioned. Being those apps do not automate or change diablo3 in any way they are not supposed to be against ToS/EuLA. You can use them and not worry about being banned.
similar specs to Demonnazo but no graphics card of course, having said that it's as slow as... I know most use Windows and special built systems but for those who use laptops... Is there any Mac users who can help me speed up? Can't access files on a Mac like Windows