Over the week on this forum I noticed couple times people saying that for some there's no need to get the iMac with best GPU, that better get the lowest and in the future, if needed, get external Thunderbolt 3 GPU.
I suspected there may be performance drop but first google result with bunch of bencharks shows it's worse than I could think, and the more powerful the card the bigger drop, 30% right know, but probably even worse with lot more powerful cards in the future. https://egpu.io/forums/mac-setup/pcie-slot-dgpu-vs-thunderbolt-3-egpu-internal-display-test/
I read posts people suggesting getting iMac with 570 (3.6TFLOPS) and if you later needed power of 580(5.5)(and cards with that power will be cheaper in the future) to get eGPU, but with the 30% drop, the 580 kind of card would be almost the same to the 570, 3.8TFLOPS.
So eGPU may be exciting and recommended for MacBooks but not for iMacs.
Thunderbolt 4 will be better so will be TB5 but also GPUs like Vega and Volta and succesors.
So not soon will Thunderbolt(whatever number in the future) be equally good to PCI Express(whatever number in the future).
So I would not count on TB3 eGPU for 27" iMac,
definitely yes fro MacBooks and 21" iMacs but not 27" iMacs right now
or I have this all wrong? I will admit I made this conclusion from just first google result
I suspected there may be performance drop but first google result with bunch of bencharks shows it's worse than I could think, and the more powerful the card the bigger drop, 30% right know, but probably even worse with lot more powerful cards in the future. https://egpu.io/forums/mac-setup/pcie-slot-dgpu-vs-thunderbolt-3-egpu-internal-display-test/
I read posts people suggesting getting iMac with 570 (3.6TFLOPS) and if you later needed power of 580(5.5)(and cards with that power will be cheaper in the future) to get eGPU, but with the 30% drop, the 580 kind of card would be almost the same to the 570, 3.8TFLOPS.
So eGPU may be exciting and recommended for MacBooks but not for iMacs.
Thunderbolt 4 will be better so will be TB5 but also GPUs like Vega and Volta and succesors.
So not soon will Thunderbolt(whatever number in the future) be equally good to PCI Express(whatever number in the future).
So I would not count on TB3 eGPU for 27" iMac,
definitely yes fro MacBooks and 21" iMacs but not 27" iMacs right now
or I have this all wrong? I will admit I made this conclusion from just first google result