> Single-thread performance it tied to clock frequency In a very loose sense. It's clock speed * instructions per clock. But even that is misleading, as the n

> Single-thread performance it tied to clock frequency In a very loose sense. It's clock speed * instructions per clock. But even that is misleading, as the number of instructions per clock is not a fixed quantity and hasn't been for decades now. It's also impacted by the instructions that came before and the ones predicted to come next. > this is exactly why ancient Core Duos, made in 2007 are still perfectly usable for office applications and even lightweight development They are suitable because these applications are not very demanding. A Core2Duo at the same clock speed of a modern processor will be much slower. > cannot go above 5Ghz Can, and have. But the cost-benefit of increasing clock speeds further is not favorable.