what i’m referring to is the whole hybrid mode/passthrough situation where dGPUs and iGPUs somehow depend on each other and dGPUs can’t really be run descretely.
oh that thats more a hardware question, which turns into a software one depending if hardware is present. basically if a manufacturer for laptops specifically deaigns a laptop that has both, they can choose to implement a hardware mux or not. the decision affects fps, latency and cost. if they lack it, software decides which ones to use and has to redirect dgpu to igpu, which is connected to the laptop screen (what causes latency and performance loss, as there is no hardware switch that goes from gpu to monitor directly)
however this odd phenomena where gpus get routed into igpu has a couple of benefits in very niche usecases and experiments. one example is that it allows for gpus that have no output to work as a typical gpu (e. g miner specific built gpus) and a joke example ia when a modder made a game run both DLSS 3.0 and FSR 3.0 frame generation by having a discrete nvidia gpu pass all its frames (including geneated ones) to a amd apu that appled amd frame gen as a propf of concept. this odd connection allows for interesting quirks not present if something is directly connected to the gpu.
no, i understand all of that, of course.
what i’m referring to is the whole hybrid mode/passthrough situation where dGPUs and iGPUs somehow depend on each other and dGPUs can’t really be run descretely.
oh that thats more a hardware question, which turns into a software one depending if hardware is present. basically if a manufacturer for laptops specifically deaigns a laptop that has both, they can choose to implement a hardware mux or not. the decision affects fps, latency and cost. if they lack it, software decides which ones to use and has to redirect dgpu to igpu, which is connected to the laptop screen (what causes latency and performance loss, as there is no hardware switch that goes from gpu to monitor directly)
however this odd phenomena where gpus get routed into igpu has a couple of benefits in very niche usecases and experiments. one example is that it allows for gpus that have no output to work as a typical gpu (e. g miner specific built gpus) and a joke example ia when a modder made a game run both DLSS 3.0 and FSR 3.0 frame generation by having a discrete nvidia gpu pass all its frames (including geneated ones) to a amd apu that appled amd frame gen as a propf of concept. this odd connection allows for interesting quirks not present if something is directly connected to the gpu.