@kruk:
It's not the textures resolution that matters, but how much you scale them.
If you use 512x512px textures and leave them at 1.00 scaling, the compile times would be approximately the same as using 128x128px textures at 1.00 scaling. But if you scale them at 0.50 instead, your compile times would be two times slower.
The real purpose of using high resolution textures is that you can cover bigger areas using smaller scales and avoid to show the texture's seams, but at the same time achieving more detail.
In my case, I use 0.50 scaling on all textures, and sometimes 0.25 to push some details in the map (don't mess too much with 0.25 scaling, definitely not recommended).
It doesn't matter how powerful your computer is, because the engine is old and can be unperformant easly if misused.
The good thing is that you don't need more than 100 fps to play any Goldsrc based game, as more fps would just create a mess with the entities (especially NPCs) making them turn really slow depending on how many frames you're getting (the more the slower). Also bunnyhopping would be harder for the same reason, being unable to maintain speed.
And yes, you could use more than 8 of those textures, it's just about HOW you'll use them.
@KB90:
Yes. Pure vanilla Goldsource.
@Urby:
I didn't know that. I thought it was 512px max for both sides.
Thanks for the info Urbeh.
@Trempler:
Thanks bro.