SamplerCLYB_4M_SDE_Momentumized

SamplerCLYB_4M_SDE_Momentumized is the pack's namesake experiment: the author's own modification of DPM++ 3M SDE - "egotisticalized by yours truly," in the README's words - with a momentum term on top. It's from ComfyUI Extra Samplers by Clybius, appears in the sampler dropdown after install, and outputs a SAMPLER for custom sampling.

Let's decode the name, because it tells you exactly what's under the hood. DPMPP_3M_SDE is the well-liked DPM++ 3M solver with its stochastic SDE stage - 3M means it uses third-order multistep correction, and the SDE suffix means it injects noise along the way, so it's ancestral and non-converging. 4M is the modification: a fourth stage added to that pipeline, plus an added SDE, "akin to how 3M samples" but one step further. The Momentumized suffix is the pack-wide treatment: a momentum term (default 0.5, −1 to 1) that carries the previous step's update direction forward, which the author candidly calls "somewhat naively" applied.

The inputs that matter:

• momentum - the pack's signature addition. Default 0.5; the range is −1 to 1 and positive values smooth the path.
• eta - the ancestral noise strength. Default 1; lower toward 0 for a more deterministic, ODE-like run.
• s_noise - scales per-step noise injection. Default 1.
• noise_sampler_type - the pack's usual menu of noise samplers (gaussian, brownian, pyramid, perlin, laplacian…).

Output: a SAMPLER for your custom sampling chain.

The honest take: this is the sampler to reach for when you already like DPM++ 3M SDE's character and want the pack author's twist on it - more noise structure, a memory term, and a slightly different texture. It's an enthusiast node, not a "this is the best sampler" button. Three cautions. It's ancestral, so treat it as non-converging: more steps changes the image rather than refining it, and you won't get a stable reproduction habit from it. The momentum term is the pack's own experiment, so sweep it on a fixed seed rather than trusting the default blindly. And on flow-matching models the knowledge base's rule applies - 3M's multistep machinery is built for curved DDPM trajectories, so on a straight flow trajectory it can fall apart; that's where you'd prefer a conservative Euler-family sampler instead.

Install is the shared pack routine - ComfyUI Manager → "ComfyUI Extra Samplers", or:

cd ComfyUI/custom_nodes
git clone https://github.com/Clybius/ComfyUI-Extra-Samplers

then restart. No model downloads; dependency kornia.