Rhino Texture Pixelisation Issue

Could anyone offer some suggestions on a graphics card and texture issue I have. I’m using a NVIDIA Geforce GTX970M on my laptop with Rhino 5 SR14 (5.14.522.8390).

In the OpenGL options I can see my graphics card details and the maximum texture size limit of 16384 x 16384.

Whenever I create a PictureFrame using a high resolution texture, I always get pixelated or poor resolution results in the viewport.

I’ve tried 16384 and downsized to 8192. For the avoidance of doubt, the textures I’m using are 16384 x 16384 or 8192 x 8192.

I’ve searched the forums but I’ve not found a solution.

Same. I can’t understand the difference between when Rhino decides to down sample and when it doesn’t. I know this is from 6 years ago but the problem persists. If someone could tell us what the maximum resolution is for a “picture” or perhaps what size file tips the scale it would be nice. I can downsize in something like photoshop but to what?! Just for clarity…
Is there a maximum file size or resolution for the ‘picture’ command?
Is there a ‘best’ pixels per inch (ppi/dpi) for optimal rhino performance?
What factors determine the tipping point for image resampling?