I'm comparing a AMD quad core 1.8ghz Lenovo laptop with a AMD quad core 2.2ghz Lenovo laptop.
Performance overall still depends on the full spec of each laptop model, but taking each CPU in isolation then obviously the 2.2GHz model is faster than the 1.8GHz one.
If you're considering buying one, you need to compare the full specs of each laptop you're comparing, not just the processor.