Texture downgrade in large battle - pc

Hello guys. I have some troubles playing large battles. When the mission start the texture load normally but after some seconds the textures of the ground and structure downgrade right in front of me even if it was previously loaded.

My rig:
I5 3570k oc 4.3 GHz
16 gb ram
R9 390x 8gb
HDD 1 tera
Windows 7 pro

I play. Solid 40 fps cap with third program. In very high graphics … Except shadows (low)

Please help!

Id check if a cpu bottleneck at that point,…

Any overclock on the video card (it would be getting hot here yes?)

Same thing here. Playing on very high settings. During the battle in the bandit camp (nest of vipers) some details like armour texture were downgraded.
Guess it´s not a tecnical problem. I think the game downgrades if there is to much going on in order to prevent low framerates or crashes.

I´m on i7, GTX 980, 32 GB Ram, Win 10

That is a little more reassuring.

Infact sometimes when we understand stuff like gtx1080 dropping to 20s framerate (in the same places our cards go low); lets us know it is game and not system.
So pretty natural for some of these things to be fixed through tweakage.
I have an M2 drive and quad channel ram on a six+ core processor and streaming assets hasnt proven a challenge yet. I will keep an eagle eye out for this one!