<p>H3 gives you 960 x 544. The obvious way to get 1080p is to type bigger numbers into the clip size boxes, and that is the wrong move. I measured it.</p><div data-youtube-video><iframe width="640" height="480" allowfullscreen="true" autoplay="false" disablekbcontrols="false" enableiframeapi="false" endtime="0" ivloadpolicy="0" loop="false" modestbranding="false" origin playlist src="https://www.youtube.com/embed/lcViA2FEWVw" start="0"></iframe></div>

<h3>The measurement</h3>
<p>Same seed, one run after the other, nothing else on the card, both finishing at 1920 x 1088:</p>
<ul>
<li>render at 960 x 544, then enlarge: <strong>188 s</strong></li>
<li>ask H3 for 1920 x 1088 directly: <strong>377 s</strong></li>
</ul>

<h3>The part that matters more than the clock</h3>
<p>The big render is not a bigger version of the same clip. It is a <strong>different clip</strong>. Same seed, different clip size, different camera position, different background.</p>
<p>So "render that one again but bigger" is not a move that exists. Once you have a take you like, the only way to keep it is to enlarge the frames you already have.</p>

<h3>Is the enlarger doing anything, or is it just a resize?</h3>
<p>Fair question, and my first test could not answer it because I was comparing two different shots. So I rendered the base clip again at the same seed and enlarged it two ways from identical pixels: once with the enlarger, once with a plain resize. On that test the enlarger clearly wins. Edges, eyelashes and lettering hold; the plain resize goes soft.</p>

<h3>The limit, said out loud</h3>
<p>Frames are enlarged one at a time, with no knowledge of the frames either side. On a busy shot that can shimmer slightly. It is a picture enlarger doing a video's job, and it is honest to say so.</p>
<p>The sound is passed through untouched. Nothing re-encodes it.</p>

<h3>What is in the file</h3>
<p>Stock ComfyUI H3 nodes plus the standard upscale-model loader. Nothing custom, nothing of mine you would have to install. You will need an enlarger model in <code>models/upscale_models</code>; I used 4x-UltraSharp.</p>

<p>My other free workflows and the written guides are <a target="_blank" rel="ugc" href="https://forgebun.com/go/civit_h3_workflows">over here</a> if you want them.</p>

MiniMax H3 at 1080p - upscale after, do not render bigger

<p>Renders at 960 x 544, then enlarges the frames to 1920 x 1088 and puts the sound back untouched. Three extra nodes on top of the standard graph. You will need an enlarger model in <code>models/upscale_models</code>; I used 4x-UltraSharp.</p>

Files with SHA256: c5894329b953f2b024ec8b7bfacd3d964b883d3c9a496da63707170eef989dfe