I was able to enlarge a smaller (12MP) image 6x, however. Specifically, when I select any size larger than 2.75x, it only gives chooses 2.75x as the enlargement. However, Gigapixel simply will enlarge the 11,648 x 8,73 pixels images from my GFX 100s more than 2.75x. I was surprised, because Topaz' website says they can be enlarged up to 6x without any loss of quality. I purchased Topaz Gigapixel AI today and it seems that the largest it allows me to enlarge most of my full-size image files is 2.75x.

I meant to say that Gigapixel AI simply will not enlarge the 11,648 x 8,736 pixel images from my GFX 100s more than 2.75x. I only use it to uprez my old images that were originally shot at 6MP. Personally I've never used it on images that size though. That's using the latest version downloaded today v5.7.3. I've not noticed any issues with maximum sizes however I did just download a GFX 100S sample image, and you're correct, I can't get it to enlarge it to enlarge it by more than 2.75x either. In playing with it a little, it seems that it caps the image size to 32,000 x 24,000 pixels, which seems like it kind of defeats the purpose because it is easy to stitch together a panorama bigger than that, and to do so without paying for additional software. I contacted Topaz but as it is the weekend, I suspect I won't hear back until Monday.

Giga pixel topaz