Why are games single-core bound on CPUs and not multithreaded? I understand why the rendering is offloaded to GPUs but what about other tasks?
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Games are commonly multithreaded.
Pretty much all demanding games over the last decade have been multithreaded. Consoles for quite a while now have had pretty low powered CPU’s with multiple cores, so developers have been forced to make multithreaded games since that’s the only way the game can he made to run adequately. However they often are only able to effectively make use of 2-4 cores. Some games do spread over many cores well, however its often programmatically difficult for developers to arbitrarily split up the work over an arbitrary number of cores. The game may, for example, use one core for rendering based tasks, one for AI and one for physics. These are discrete packages of work that can be nicely partitioned across a core each. Inevitably one of these tasks uses more CPU power than the others, so performance is limited by whatever that core needs to do. This means “single core performance” is often the most important factor in a gaming CPU, but that’s only because nowadays basically every CPU on the market has at least 4 cores, and if we’re comparing a CPU with 4 strong vs 8 weaker cores, the 4 core one would frequently be better even though on paper the 8 core cpu had more number crunching ability. There are crazy processors that are consumer accessible nowadays with 32 or even 64 cores, but they might not give much benefit in games since to cram this many CPUs on a single die you have to lower the power of each one.
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