I have a Pavilion dv8 with a I7 Q820 CPU. I would Like to upgrade the CPU. What might work? HP will not give me a clue. This Laptop was made only for 6 months. Has an 18.4" LCD and every bell and whistle I could buy in it. I would like to up grade to a Q920.
Upgrading the CPU in a laptop is generally not a good idea. Laptops may not always look like it, but they are very precision machines, especially when it comes to cooling. You have very little margin for error when dealing with any increase in thermal output of components in a laptop because there is far less room for that heat to dissipate inside the case. If you upgraded the CPU, then you'd need to make sure that you got an appropriate heatsink that can handle the extra waste heat generated by the CPU, and also a fan that would bleed off that heat and expel it from the case. With a desktop this wouldn't be a problem, but laptops are a whole other story, and it would be difficult at best.
My advice would be to just deal with what you have. You can check the BIOS settings to see if for some reason hyperthreading is disabled, which should get the extra virtual cores showing up.