Why is Java using 88% of my CPU?

[Paradox]

Java isn't using a BIG chunk or a lot of my computer.

With roblox, 5 websites, a chatbox, twitter, music player, skype, my cores hit 30% as the max.

What CPU do you have?

I plan on getting the i7 2600 Sandy Bridge CPU for $300. My cousin got it and he is lucky to get anything to make it go over 10%. (He was running CoDMW, CoDMW2, Roblox, and Minecraft graphics on Far settings)

I have the Intel i5 on a Samsung laptop/netbook. It is pretty good compared to all the other computers I have used.