Real HD Face Textures 2k  

If you're having issues with stuttering or freezing, try the BA2. A fantastic job made by Di3sIrae, In fact, I recommend installing the BA2 Main, then any of my loose faces, so you'll have double chances of not getting brown faces if you use a body mod that might come with a different resolution face. Remember to override or load the chosen face after any other face mod you've installed.
RealHD Face 2K - ba2 and guide

I always had a problem, maybe for many Fallout 4 users this was not a annoyance, but for me was terrible, the Limit of the face Textures of 1024x1024 for the face Difuse and Normal Maps textures, and not only that But the terrible 512x512 Specular Face textures.

i spended almost all my time while making mods to found a way to make the face textures higher, after a long time i get the answer, and it was in front of me all the time, it was not pleasant to do this way, but is the only way i found for now.

so what this mod does is double size for all the face parts textures related, and the faces togheter, now all the textures Have 2048x2048 Difuse and Noemal Maps and 1024x1024 Specular Mods.

Please Read this part carefully.

Like said in introduction, this mod will double all Face Related Textures, this means that no mod like Face tattoos Make-up etc... will not be compatible unless they are the same Size of the face, i did a patch for the Looksmenu compenfium, that will be posted on his mod page.

This Mod is compatible with any Body texures that respect the Vanilla Collors, i highly recommend using my Natural Mods in recommended section, since i worked in this mod using them all the time. 
The Males are also compatible with all beards even from mods, and both sex is fully compatible with any hair mod.

This Mod Have Two Main Files:

The Real HD Main File
the core and will make the Vanilla works in 2k i resized to the right size and formats everything to make the Vanilla Game Faces related 2k, so if you just want a Vanilla game, install this one, and this one can be useful for people who alread have a face mod and dont want to change, but have in mind that you need manually resize the Face Textures you use to the same size included in this file to work. i will not do Patch for other faces mods alread launched except my own work.

Real HD Faces Textures
My Retexture of the Male and Female Faces like you can see in screenshots, i tried my best to make a real hd texture mixing another faces mods and the ones i alread did in my previous mods, all is reworked and will include my Latest edit materials, Please take Note that this mod only will work with The Real HD Main File  Installed, dont try without or you will get a Black Face.

About Permormance:
i have a mid end machine, and im using npc replacers, Like Better settles, Keke all in one npcs etc.. and until now i dont noticied a performance drop at all

There's no big issues that i have found yet, the only one i found was a little freezing on the Showlooks menu and in character creation when changing sex, the freeze is just for few seconds and then will back to normal.

Black faces:

This bug will happen if you load a character with any face part in differen size of the Faces,
ex: a Eye

brow mod, or a make-up, lips etc... that is not in the right size, to avoid that i highly recommend to remove all Face parts (eye textures not included) mods you may have before install this Mod, and if you use the LooksMenu Customization Compendium   make sure to install the Patch to this mod.
if the bug persist use the LooksMenu by Expired6978      enter the Character Creation by Pressing SLM in command and then The E to go to Makeup area  and then Press R to erase all, press ESC to back and and then R to enter the Preset selection, Save the new Cleaned Character Pressing X the Save, and then Load this new Cleaned Character.

About the Glow... I edited the Materials to activate the Sub-Surface textures; the reason being that it looks more realistic in some lighting, however if your sun or HDR is too strong, sometimes the glow can appear much stronger and look odd. If you do not like the effect, you can go to the following folder..

Data\Materials\Actors\Character\Basehumanfemale 
...and delete the following files... 
Basehumanfemalehands.bgsm 
Basehumanfemaleskin.bgsm 
Basehumanfemaleskinhead.bgsm 

final note:

With This method is possible to make a 4k ultra HD Face Mods, but after many tries, when trying to enter the characer creation, be that for new game or SLM command, my game freezes and dont come back, maybe my machine cant handle that, maybe is a engine problem, so since i cant confirm, no 4k for a time.