I haven't done it myself so I'm mostly speculating but I would expect a separate GPU to be easier to cool passively if it is performing as poorly as an iGPU wou

I haven't done it myself so I'm mostly speculating but I would expect a separate GPU to be easier to cool passively if it is performing as poorly as an iGPU would At the end of the day it's all watts and surface area isn't it? Dedicated gpus are intended to perform better and allowed to draw more watts to do so. If you lowered the clock speeds and power limits down to what igpus are allowed to use, you'd then have a much larger surface to dissipate heat from and not share it with the heat from a CPU, so it should be easier to cool. But id also expect anyone wanting to passively cool their system to also care about things like cost, size constraints, weight, number of parts that can fail etc so in practice just using an iGPU will probably make more sense.