I think its ok for the imac to can handle dual eGPU in bootcamp?
i wonder if its even possible ? to connect 2x eGPu from 2 TB3/usb-c ports
Possible to connect? Absolutely. Able to "handle?" Most likely, although it depends on what you mean by "handle."
Theoretically, the iMac should be able to physically see a many eGPUs as as you can connect.
Windows should let you use them
with an external monitor they are connected to with relatively little hassle (assuming the enclosures are TB3 and can provide sufficient power).
If you want to CrossFire/SLI them, this will be a bit more work, but only because you'll either need a dual card enclosure (none exist as far as I know) or a long bridge.
macOS should also be able to use the GPU's for the external monitors attached (and for OpenCL/CUDA), although it currently requires a fair bit of tweaking.
Neither macOS, nor Windows is going to let you drive the internal iMac display with more than one GPU though, and whether or not people can even hack together a solution to get one eGPU properly driving the internal display is still up in the air (best case scenario, be prepared to shave off 30% or more performance to do so.)
Anyway, you probably won't want to go beyond the number of physical TB3 controllers (not the same as ports) the iMac has on its logic board, as each additional GPU beyond the number of controllers will result in reduced available bandwidth for all TB3 devices, which I would imagine could quickly lead to diminishing returns. Just as importantly however, given the cost of TB3 enclosures, I can't see too many scenarios where its really worth it to invest in more than one. If you actually need 2 GPUs that are more powerful than what the iMac itself offers, you should probably be looking at investing in a (n)nMP (whenever that comes out), or a PC/Hackintosh.
But yeah, as far as I know its certainly doable
🙂