I have a laptop with

* Intel i7 2720QM
* Samsung SSD PM810 128GB SATA II [(link to benchmark](http://www.ssdreview.com/review/compare/samsung-pm810-128gb-axm0601q/))
* 8GB DDR3 PC-10700 Memory CAS# Latency 6/7/8/9
* My internet speed is 19 ms (Ping) 20 Mbps (Down) 4.5 Mbps (Up)

but I still experience some lags in my firefox / Google chrome when I have many tabs open, and my ram is not even half full. On another note, I also use 20+ extensions.

What is the bottleneck here? Is it the web browser not taking advantage of multiple cores? Or is the latency in the RAM? Or is it the cache in SSD?