Problems tiling displacement

[capacitycorp]

I've run into an odd problem while doing some displacement based grass. I'm feeding a 4k noise image into the displacement channel. When I scale down the noise too much within the image, I get some really strange artifacts/ patterns in my renders. As far as I can tell, there are 2 different problems going on. 1) I can actually see the edge of each of my geometry "tiles", as well as a diagonal line through the middle. 2) Theres a sort of arc or hemisphere shadow that actually seems to follow the camera. If I turn off displacement or scale up the noise these effects go away.
Any thoughts anyone?

[bepeg4d]

Hi capacitycorp,
since Octane displacement is strongly related with uvs, instead of changing the scale of the texture in the node image, use the uv command in the attribute of the matetial tag.
Alternativelly, create a texture with four tiles or more in PS to scale down the input image.
ciao beppe

[capacitycorp]

I've tried scaling the UV in the material as well and seems to have the same result. Here's a sample scene if you wanna check it out.

[capacitycorp]

Oh and in case you were talking about selecting the Tag itself and scaling there, I can't do that because I'm overlaying UV based color onto the grass.