Attached Link: Rendering hair

Don't use Texture filtering.  It will eat up memory like crazy, and may do bad things to other textures in your scene.

Instead, lower the shading rate.  (Of the hair, in Properties, and in your Render Options.)

This will slow the render down, so you might want to wait until the final render.  I use a shading rate of 0.01-0.05 for Koz's hair.

See the link for more details.