💡 The paper proposes a training-free acceleration strategy for text-to-image diffusion models called MrFlow. The problem with existing multi-resolution generation strategies is that they can produce noticeable blurring or artifacts due to upsampling in the latent space and selective modification of partial regions. MrFlow addresses this issue by using a staged low-to-high-resolution pipeline. It first generates the main structure at low resolution, then performs super-resolution in the pixel space using a lightweight pretrained model, injects low-strength noise to enable high-frequency resampling, and finally refines the details at high resolution. The results show that MrFlow achieves a 10x end-to-end acceleration while maintaining a high level of image quality, with only a 1 percent gap in performance compared to the original model. Additionally, MrFlow can be combined with other acceleration strategies, such as timestep distillation, to achieve even higher acceleration of up to 25x. The key advantage of MrFlow is that it does not require any training or runtime modifications, making it a hardware-agnostic and efficient solution for accelerating text-to-image diffusion models.