Do some games revert to using simpler algorithms depending on cpu?

[Commenter]

With dynamic resolutions now becoming a thing in console games. I wonder though if it's common for pc games say to revert to different, less intensive software algorithms when detecting a lower end cpu or if the cpu is at full load?

 

[Davros]

Games certainly run different amounts of threads depending on how many cores the cpu has
no mans sky version 1.0 used sse 4.1 meaning that it would not run on core2 and some amd cpu's
it was later patched to use a lesser version of sse but i would imagine it uses sse 4.1 if detected
grid and grid 2 use codepaths specific to some intel cpu's (avx) to enable OIT Order Independent Transparency for smoke effects.

Also games run diferent code depending of capabilities and power of graphics cards
and example of this would be physx.
or in the game Rage it supports the texture transcoding on the GPU feature by way of NVIDIA's CUDA technology.
Just Cause 2 also used CUDA to calculate waves.

 

[Commenter]

I meant actually are there any examples of a game switching to a simpler AI routine, or less accurate hit detection or simpler physics calculations under load?

 

[Pixel]

Sure but they leave it up to the player to to determine if they want the performance impact at the cost of the inproved cpu simulations via settings. They don't shoehorn you into a specific setting because of your hardware.

For PC with its multitude of hardware configs players want and need control and options and choice for settings. That is why higher settings are not locked out even if its not ideal for their hardware.

Crysis lets you chose varying levels of cpu bound physics simulations depending on the physics settings you chose.
Starcraft lets varying levels of non-game impacting cpu bound physics simulations for debris and unit destruction, it also lets you adjust # of sound channels from 16 to 128.
GTA, Bethesda and likely other open world games have draw distance settings that impact not only increase gpu demands but also further the distance various cpu bound simulations and scripts are running.
I've heard post processing and particle simulations for some past games have often relied heavily or completely on the cpu.

Developer Shiny's "Messiah" had a cpu based polygon scaling algorithm (some argue that this is an early example of tessellation) for characters. You could manually adjust character polygon complexity it in the menu based on your cpu, though i'm not sure if the game would auto detect existing cpus at the time and pre-adjust settings like games do nowdays.