MiniMax H3 Slowdown on 12GB Cards? A ComfyUI VRAM Troubleshooting Guide

BrooklynBrawl · reddit · 2026-08-06

This post details the troubleshooting process for a severe generation slowdown (degrading from 18s/it to 400+ s/it) when running the MiniMax H3 model via ComfyUI on a 12GB RTX 4070 Ti.

Root Cause

The author identifies ComfyUI's newer comfy-aimdo DynamicVRAM feature as the culprit. Under VRAM pressure and an existing memory leak, its aggressive allocation tipped memory over into the drastically slower system shared memory overflow.

The Fix

Adding --disable-dynamic-vram and --disable-pinned-memory to the launch flags resolved the slowdown and memory climbing issues. The article also shares a timeline of fixing initial int8 crashes, OOM errors, and configuring SageAttention.

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