FL SDUltimate Slices

Don't let the name fool you - this isn't an upscaler. It's the little math helper that sits next to one. FL_SDUltimate_Slices takes an image, a grid choice, and a multiplier, and tells you how big each tile would be. That's it: it computes slice_width and slice_height for a tiled upscaling setup so you can feed those numbers into the node that actually does the sampling. Think of it as the tape measure, not the saw.

Tiled upscaling - splitting an image into overlapping tiles, sampling each, and blending them back - is how you get to big print-size resolutions on limited VRAM. The community's tiled workflows (Ultimate SD Upscale and friends) live and die on getting tile dimensions right, and this node exists to take the arithmetic off your hands.

How it works

You pick a slicing grid from 1x1 up to 4x4, set a multiplier, and pass in your image. The node reads the image's dimensions, divides them by the grid, applies the multiplier, and hands back the resulting per-tile width and height (plus the multiplier itself, so it can travel downstream). A 3x3 on a 3072-wide image gives tiles a third as wide before the multiplier scales them. Those numbers then drive whatever tiled sampler you're pairing it with.

Because it only calculates, it's cheap and instant - no sampling happens here.

The inputs and outputs

• image - the image you intend to upscale (it reads the dimensions).
• slicing - the grid, 1x1 through 4x4. More slices = smaller tiles = lower VRAM per tile but more tiles to process.
• multiplier - scales the computed slice size (1 to 4, in 0.25 steps).

Outputs: image (passed through), slice_width, slice_height, and multiplier. The width/height ints go into your tiled upscale node.

Installing it

Part of the Fill-Nodes pack. ComfyUI Manager: search ComfyUI_Fill-Nodes, install, restart. Manual:

cd ComfyUI/custom_nodes
git clone https://github.com/filliptm/ComfyUI_Fill-Nodes

then restart. The "Machine Delusions" banner on startup is just the pack's splash.

Where people get tripped up

• It doesn't upscale anything. This is the single most common confusion, and the name invites it. FL_SDUltimate_Slices is a dimension calculator that feeds a separate tiled sampler. If you wired it up expecting a bigger image out and got the same image plus some numbers, that's working as intended.
• Not the same as Impact Pack's UltimateSDUpscale. The well-known "Ultimate SD Upscale" node - the one people actually run for tiled upscaling - lives in other packs. This Fill-Nodes utility is a helper for that style of workflow, not a reimplementation of it.
• More slices isn't automatically better. Smaller tiles keep VRAM down but multiply the sampling passes and add more seams to blend. And remember the upscaling rule of thumb: tiled sampling without a ControlNet Tile condition lets tiles drift from the source and creates patchwork. The tile size is what this node solves; the tile coherence is a job for the sampler you feed it into.
• Fix defects before upscaling, not after. Whatever tile math you use, faces and hands should be sorted at native resolution first - upscaling bakes in artifacts.