Texture filtering off on textures perhaps, but also lower the minimum shading rate to 0.2 (ish). Raising pixel samples also helps.

I've just had a nightmare of my own with texture filtering on displacement maps - definitely set to 'none' for those (on my system at least). I couldn't even get a render to complete with it on.

 

PoserPro2014(Sr4), Win7 x64, display units set to inches.

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