Pro-consumer, anti-DRM. Never be satisfied with any answer. Dig until you drop.
2.1 GHz and 2.9 GHz? Not sure what you mean there.
Note that the Dual Celerons are really slow by today's standards, although modern-day Celerons can be fairly good for low-end computing. Not sure I'd trust it with a CPU-heavy game like Football Manager, though.
You can find out more by looking up the model and Googling some benchmarks.