I have recently upgraded my system from Ubuntu 12.04 LTS to Ubuntu 14.04 LTS. In the beginning everything was fine. It has been happening from 2-3 days that whenever I play any video on youtube, mozilla firefox hangs for 5 seconds, then responds for a second and then hangs once again so that I have to force close the browser. Any solutions to this problem?
$lscpu Architecture: i686 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 4 On-line CPU(s) list: 0-3 Thread(s) per core: 2 Core(s) per socket: 2 Socket(s): 1 Vendor ID: GenuineIntel CPU family: 6 Model: 42 Stepping: 7 CPU MHz: 2501.000 BogoMIPS: 4989.08 Virtualization: VT-x L1d cache: 32K L1i cache: 32K L2 cache: 256K L3 cache: 3072K