I currently am using an HP with a processor speed of 2.20 GHz
The actual real-world performance of this HP depends on a lot more things than just processor speed. For example, how old is the HP? What processor sticker does it have on it? If that 2.2Ghz processor is a single-core Pentium 4 processor (common on PCs 3 or so years ago) then that HP is likely dog-slow compared to a dual-core 2.26Ghz modern Macbook. But if the HP is brand new and the 2.2Ghz processor is the same family (Core 2 Duo) as the Macbook, then they are likely very similar in speed.
The other thing to consider is OS X vs. Windows. Macs of the same processor speed have always seemed a little faster than Windows machines (at least to me) and Snow Leopard makes that gap wider. Windows 7 and Vista are both so resource-intensive that a 2.2Ghz Mac is likely to feel faster than a 2.2Ghz PC. Especially if they both only have 2GB of RAM.
What do you intend to use the machine for?
--Travis