Progressive Distillation (Salimans & Ho 2022, ICLR) was the first principled attack — train a student model to take steps twice the size of the teacher, repeat the procedure, and halve sampling steps each round. Run it 4 times and you go from 1024 steps to 64. The technique worked but plateaued around 8-step quality.
Consistency Models (Yang Song, Prafulla Dhariwal, Mark Chen, Ilya Sutskever, ICML 2023) reframed the problem: instead of incremental halving, train a single function that satisfies a global consistency property across the entire trajectory. This was the breakthrough that made 1-step generation viable.
Latent Consistency Models / LCM (Luo, Tan, Liu, Guan, Zhao 2023) ported the idea to Stable Diffusion's latent space — and crucially, released LCM-LoRA (December 2023), a low-rank adapter that converts any pretrained SD model into LCM with minutes of fine-tuning instead of weeks of full retraining.
Adversarial Diffusion Distillation / SDXL Turbo (Sauer, Lorenz, Boesel, Rombach, Stability AI, 2023) added the GAN discriminator and pushed quality high enough for production use at 1-4 steps.
Hyper-SD (Ren et al., ByteDance 2024), Flash Diffusion (Chadebec et al. 2024), PCM (Wang et al. 2024) refined the family further — multi-stage distillation, trajectory segmentation, and various tricks that pushed 1-step quality close to 50-step teacher quality.