Android - What do I need to improve performance of the Android emulator?

Past versions of the emulator were extremely slow on all platforms. However, there are now native x86 versions of the emulator; performance should be considerably improved. You should be able to get them through the Android SDK (or through Intel's website, see this Stack Overflow post).

However, I would recommend (for end users) Memu instead; it's very fast and reliable. Genymotion is the best alternative if you aren't on Windows.