Install the latest BIOS for your motherboard. That would be a good place to start. Replacing the stock cooler with an aftermarket cooler that is a lot more capable, would be a close second in terms of being helpful.
Also, I would be a LOT less worried about losing performance from a 100-200mhz difference in CPU clock speed, for now anyhow, then I would about the fact that you only have a single stick of memory installed and are not able to take advantage of doubled bandwidth like you would with two sticks running in dual channel.