What memory is Better????

I want to upgrade my Envy 14 from 4g to 8g but I am confused, which is better for my computer the DDR3 PC3-10600 or the DDR3 PC3-8500 memory (non-ECC.)
Whats the difference between the 2, they both are compatible?

By upgrading from 4 to 8g will this make my computer faster or slower? Will upgrading my system to 8g help or hinder my computers performance???? I was under the impression that increasing my memory would help my overall performance or is this a misconception????

 

increasing memory is always a good thing, 4gb should be considered minimum, and 6-8gb standard these days (on consumer systems running a 64bit OS). you can do more things at once without hangs and the system may boot up faster, as well as apps with lots of ram usage may perform (including games!).

the difference between ddr3 pc-8500 & pc-10600 is its clocks, 1066mhz & 1333mhz respectively, so the higher the clocks, the faster it performs.
dont bother ECC, you dont need it if you dont know you need it.

since your notebook supports 1333mhz, go for 2x4gb ddr3 pc-10600 (higher clocked ram may eventually run downclocked to 1333mhz if you put it inside, so it would be a waste of money; but you can still try it and if it runs higher then everythings ok).
the crucial ram you mentioned in your previous post regarding HP's ram pricing is a good one, as i already told you there.