I'm running Morrowind with MGE XE on 1920 x 1080 resolutions with maxed out settings and getting about 25 FPS. Playable, but with maxed settings I get 60 FPS with Oblivion and 40 FPS with Skyrim.

It depends what mods you're using especially textures, graphic replacers but also if you're using NPC intensive mods like MCA. So your loadorder needs to take a closer look at, could you post it please.

Morrowind with MGE is much more demanding than Skyrim.
Morrowind is an old game not designed for modern PCs, and was never meant to be displayed with Distant Land, high resolution, etc.

Morrowind with MGE XE : Skyrim :: Teaching an australopthecus mathematics : Teaching a human mathematics

It's a lot slower and there's only so much you can do.

This is why OpenMW and its development is such a big deal for a lot of us.

"Max Settings" could mean a lot when talking about MGE XE...

If you tweak it a bit you can get some decent performance, but yeah it's still not gonna be great.