why hello there??? im assuming the question is in the title. the x4 630 is a quad core with no L3 cache, but a decent clock speed. MOST games dont utilize quad cores and mostly benefit from L3 cache and clock speed. so something like the x2 555 (not unlocked) would beat it in a lot of current games. however, things are changing, so more games are starting to use 4 cores, so it depends on what games you play.
there are 3 levels of cache, L1, L2, L3. each one is almost always progressively bigger than the previous. cache is like the computers speed dial, it holds a small amount of things, but its extremely fast in opening them. Its partially why once you open up an internet page, it opens up faster after that since its store in your cache. Thats when when you delete "cookies" you are clearing your cache. Most parts have cache, cpu, hard drive, not RAM as RAM basically is a big speed boost, but there you have it. L3 cache helps a decent bit on gaming. The Athlon series has no L3 cache, they have 2MB of L2 cache, 512KB per core. say, the amd x2 555 callisto, a part of the phenom family does have L3 cache. It has 1 MB of L2 cache, and 6MB of L3 cache. This is the main difference between the athlon and deneb family, besides minor arch. differences.