OT: I think it also shows the bad iGPU compared to Apples offerings, so too many x86 laptops have additional GPUs, which reduces battery life (we'll see what Strix brings)
Also both have 16 performance cores, but the Ryzen is faster in multicore. The Ryzen is one year later b/c due to node access/ costs. Doesn't look like "far behind".
There is nothing inherently inefficient about a discrete GPU. Discrete GPUs often have extremely good performance per watt. That's just not the same thing as having a low TDP. Performance per watt is higher when something is twice as power hungry but three times faster.
Not an electrical engineer, my GPU board has lots of additional chips and VRMs, and I do think those should take additional power. All of these are cooled which means they convert power into heat, so I would assume a discrete board draws more power than a SoC. But as I've said, not an electrical engineer (Just some electrical engineering exams at university).
In principle you can shut off anything when it's idle and get its power consumption arbitrarily close to zero.
Discrete GPUs obviously use more power because their use case is when the iGPU isn't fast enough. Hypothetically you can make a discrete GPU with the same performance as an iGPU and it would be no more power hungry. These have occasionally been available, basically monitor cards for CPUs without an iGPU etc. But the ones with a lot of fans and VRMs have them because they do indeed use a lot of power -- which isn't the same as having poor performance per watt, because they're also really fast.
OT: I think it also shows the bad iGPU compared to Apples offerings, so too many x86 laptops have additional GPUs, which reduces battery life (we'll see what Strix brings)
Also both have 16 performance cores, but the Ryzen is faster in multicore. The Ryzen is one year later b/c due to node access/ costs. Doesn't look like "far behind".