I give you a variety of points and all I get back is a single flip quip. This is a disappointing rejoinder.

You CAN have a high end desktop. You can even have 3-6 monitors if it makes you happy. The only thing you cannot do is plug your monitors into the outputs of both GPUs. You must purchase GPUs wherein a single GPU has sufficient outputs and let the secondary GPU serve to aid in your favorite GPU compute or game playing adventure.

For example

https://www.newegg.com/gigabyte-radeon-rx-vega-64-gv-rxvega6...

This supports 6 displays and crossfire so it plays well with lots of displays and multiple GPU.

Stepping up further in price

https://www.newegg.com/evga-geforce-rtx-2080-super-08g-p4-32...

Supports 4 displays and SLI

Is it possible to have two cards and have the second card do computations for the first one to render? I would have thought the time it took to move the data would make that hard.

Generally one actually runs games on one monitor in the first place so this is the only way it even could work. Work can be divided up by frame for example.

Crossfire and SLI rely on a high speed interconnect and game specific support.

Dual GPU is a much smaller niche than "high end desktops".

Multiple gpus are even supported just not outputs hooked up to both GPUs as a single X screen.

https://wiki.archlinux.org/index.php/NVIDIA/Tips_and_tricks#...