WHAT MAKES A CPU FAST?
CPUs may all do the same broad job, but they’re not all alike. As the benchmark scores in our reviews confirm, the chips found in lightweight laptops are nowhere near as powerful as the heavyweight processors used in graphical workstations and gaming desktops. In this feature, we’re going to explore exactly why.
Perhaps the simplest reason is that different models run at different speeds. If one processor runs at 3GHz and another runs at 4GHz, it’s pretty obvious that the latter will be faster to complete a given task.
This raises the question of why anyone bothers making processors that run at slower speeds. One reason concerns manufacturing challenges. There’s never any guarantee that every chip that comes off the assembly line will be stable at its target speed: tiny, sub-microscopic variations between chips are almost inevitable, and that can have a significant effect on how hot a particular unit gets. This matters because if the chip overheats, the whole processor – and the computer it’s housed in – is liable to crash.
To deal with this, chip manufacturers test their silicon before selling it; chips that are perfectly stable at 4GHz will be sold as such for a pretty penny. Others might not work reliably at 4GHz, but run just fine
