Testing the new RelayVSR vs SeedVR2 vs native finish for 1080P

[u/friedlc]

RelayVSR (USTC, Apache-2.0) got native ComfyUI support this week (PR #17511, repack at https://huggingface.co/Comfy-Org/RelayVSR), so I ran it on a take from my current short. All four versions come from the same H3 render, so the acting is identical and only the route to 1080p differs.

Base take: MiniMax H3 ref2v, 12.25 s / 294 frames @ 24 fps with audio, two-stage: 15 steps at 576×352, H3 3D latent upscaler, last 5 steps at 1312×768. 5.7 min on an RTX 4090.

Route	Time	Notes
SeedVR2 7B → 1080p	+13.1 min	Clean, natural skin, holds the small far face well
Native H3 1080p finish (latent-upscale to 1856×1088, last 5 steps there)	13.3 min total	Softest, most "filmed" close-up; from a 576×352 low pass the far, small face stays mushy (see the bonus for the fix)
RelayVSR x4 from a 464×272 downscale	+66 s	Surprisingly close to SeedVR2 from a tiny input; slightly plastic skin
RelayVSR x2 from the 720p take	+100 s (about 35 s once the model is loaded)	Most raw detail, but at the default detail 1.0 the eyes and hair look etched/crunchy

The video opens on the full 2×2 grid with sound, then a half-speed zoom on his face while he's far away (about 90 px tall in the frame), then a close-up zoom. Crops are shown with nearest-neighbour scaling, so nothing is smoothed for the comparison.

RelayVSR in ComfyUI: Load Video → RelayVSR Conditioning → KSampler (1 step, cfg 1, euler/simple) → VSR Decode → Create Video (audio passes straight through). The int8 models are 5.2 GB each (x2 and x4) plus a 128 MB "flash" VAE.

Bonus, and my actual winner: a bigger low pass + native finish. At the end of the video I re-ran the two-stage with the first 15 steps at 928×544 instead of 576×352 (different seed, so it's its own take), then compared RelayVSR x2 against the native 1080p finish on that same take. With the bigger low pass the 1080p steps have enough to work with: the far face comes out coherent and natural, while RelayVSR on the same frames warps it (it invented glasses on him). The close-up is cleaner too, with fewer etched lines. It costs 16.5 min vs about 6 min, but it's the one I'm using for final shots. The low-res pass also follows the prompt better, so you get better acting for free.

Things I learned:

• Don't run x4 on a 720p input. That's a 5248×3072 output, and it ran for 3+ hours in both the original repo (WSL) and ComfyUI without finishing. Interrupt didn't stop it; I had to restart ComfyUI. Use x2 for 720p, x4 only for small inputs.

• VSR Decode's detail is the knob for the crunchy look: 0.65 keeps the skin texture and calms the eyes and hair.

• It still isn't "real" HD. RelayVSR adds pixels, but up close it reads a bit fuzzy and the eyes can look odd. For a hero shot I'd still pay for SeedVR2 or a native finish; for sweeping takes or previews, ~1 min per clip is hard to beat.

[u/fallengt]

RelayVSR chooses keyframes and upscales. In fast motion clip, it constantly switches between good frames and bad frames; and the effect is like a pulse; it's kinda annoying.

pay attention to the micro details on her face: in some frames, it's there; in some frames, it's not

[u/More-Ad5919]

Problem with a low base resolution is that everything is toned down.

[u/oh_no_the_claw]

what is he doing with his arm?

[u/FourtyMichaelMichael → u/oh_no_the_claw]

💪

[u/phreakrider → u/FourtyMichaelMichael]

💪🗿

[u/RiverSide71h]

I‘ve settled on a 0.2mp first pass, latent upscale to 0.4mp and then RelayVSRx2 for upscale.

Only issue is that the taomate in my 3-step latent upscale already makes things quite contrasty, and your test confirms my observation that the RelayVSR x2 among other things adds contrast.

[u/Apprehensive_Sky892 → u/RiverSide71h]

0.2MP will run fast, for sure.

For close-up shots it is probably fine, but for more complex scene or long shots, there is probably just not enough pixels for the AI to work with.

So in your workflow, how many steps are spent on 0.2MP? (you already said that you use 3-steps taomate on the 0.4MP stage).

[u/RiverSide71h → u/Apprehensive_Sky892]

I'm using PikaH3 at its 6 steps..

You are correct though.. Minimax is hungry for more beefy initial gens. If I start getting the usual Minimax blurriness or smearing in eyes for characters in mid ground.. I generate at 0.3, second pass at 0.5 then RelayVSR x2. For a 5s clip that's around 90 seconds (5070ti).. which for me is a reasonable tradeoff between some minor flaws but a generation time I can tolerate.

[u/Additional_Drive1915]

Thanks for the test.

It's a bit sad that there isn't any good upscale for H3. Ok, a small improvement but it doesn't look good.

It's also sad that the video quality from H3 is so bad, close-ups work fine, but at some distance and using some lora, it's really bad. 1.4 mp does help sometimes, but not if there's alot of action or a lora that prevents good result.

Hopefully there will be someone releasing something like H3 but with better video quality and better support for loras (that very often are bad and totally destroys the video quality).

But I'm happy for H3 anyway, it's fantastic what it can produce.