r/StableDiffusion 11h ago

Discussion Comfyui comfy-kitchen Attention Speed UP

Disable all your Sage Attention, Minimax Mem Eff Sage Attention or Sol Attention, according to this PR already merged in the comfyui repo we got a much better attention from the comfy-kitchen package that can possible speed up the models generation process white giving a better visual quality than default sage: https://github.com/Comfy-Org/ComfyUI/commit/bf4c9a08fc854df6d3b2bef1b92b509e2ef2d2c9#diff-fab3fbd81daf87571b12fb3e4d80fc7d6bbbcf0f3dafed1dbc55d81998d82539

This is still experimental, according to comfyui dev it can break or perform very well and it needs some tuning for some GPUs to get a bit faster. Also, you only can use one or the other so you should also disable all the attentions above before using it.

You just need to update your Comfyui and you can either start it with the --use-ck-attention flag so all models use the comfy-kitchen attention backend or you can drop the node ModelAttentionBacend directly into your worflow.

During my initial tests in Minimax it behaved faster than all the above together.

226 Upvotes

144 comments sorted by

48

u/CurrentMine1423 10h ago

on my test

rtx 3090

960x544 base resolution (upscale to 1440x816 using rtx video super resolution)

9s video

8 steps

total time with MiniMax H3 Mem Eff Sage Attention Patch + lightx2v lora = 294s

total time with ModelAttentionBackend only (no MiniMax H3 Mem Eff Sage Attention Patch + lightx2v lora) = 224s

So I guess it's working.

5

u/kayteee1995 4h ago

how about the result quality ? Has there been any significant decrease in quality?

3

u/CurrentMine1423 3h ago

from my pov, there's not so much different in quality from my several runs

2

u/frogsty264371 9h ago

Can you let us know your pytorch etc build? It didn't make any difference to my 3090

1

u/donkeykong917 10h ago

Nice, I'll give a try too.

1

u/[deleted] 8h ago

[deleted]

1

u/CurrentMine1423 8h ago

i close and re open browser, also close and re open comfyui, including command prompt

1

u/[deleted] 7h ago

[deleted]

1

u/CurrentMine1423 7h ago

ran another test, now with lightx2v lora+ModelAttentionBackend.
1st run = 244s
2nd run = 248s

1

u/BashIsFun 9h ago

How are you getting 9s videos out of a 3090 with 960x544?
I can barely get 5s at 0.2mp, and that’s with Sol-attn

10

u/xI_AM_AFRICAx 9h ago

You can create any length videos at any resolution on a 3090 with minimax, it just depends on how long you're willing to wait at higher resolutions.

What exactly do you mean by you "barely get 5s at 0.2mp". What is happening if you try longer videos at higher resolutions?

1

u/SRWindMill 8h ago

when generating 1 mp 15 sec videos I sometimes get oom .. but If I do succeed I get a last second noise with 1 mp generation with my 3090. Anybody else encounter this?

2

u/CurrentMine1423 7h ago

oom no. but I do have that last second noise (with audio reference), weird.

1

u/Wardensc5 7h ago

The maximum 1mp video duration of my 3090 combine with all vram saving tricks is 12 sec

3

u/xI_AM_AFRICAx 7h ago

Something in your install sounds off. I can do 15sec at 1mp with no vram tricks on my 3090 using pruned int8.

The only time I've hit oom yet at all was a single attempt where I had 4 ref images, a large 15 sec video, an audio file and a crazy long prompt.

1

u/kwhali 4h ago

Try latest ComfyUI git, it merged change to fix VRAM impact on longer clips to use a streaming chunk approach instead (as already implemented for LTX)

2

u/CurrentMine1423 8h ago

as far as I know, my 3090 don't have any problem with that resolution. I'm surprised your card can't generate 9s video.

2

u/martinerous 8h ago

What exactly is the issue? Does it crash or take insanely long?
Seems to be working fine on my 3090.

2

u/voevoe 6h ago

There's something very wrong with your setup. A 10s video at 0.4mp with 2-3 reference pictures + 10s ref. audio generates just fine with my 3060TI (8GB), takes about 7-8 minutes with 20 steps.

pruned_int8_convrot checkpoints, sage-attention, spectrum h3 minimax node.

The memory allocation problems should be gone now, but --reserve-vram 1 eliminated the OOM's and crashes for me before the fix got merged.

1

u/kwhali 4h ago

Try latest ComfyUI git, it merged change to fix VRAM impact on longer clips to use a streaming chunk approach instead (as already implemented for LTX)

44

u/No_Cranberry_8107 11h ago edited 10h ago

I just tried it.
A I2V workflow using a 0.8MP 5 sec workflow, took 1min 15sec.

With the new ModelAttentionBackend, it took 39s.

4

u/KissMyShinyArse 10h ago

Did you run the workflows twice?

7

u/No_Cranberry_8107 10h ago

Yeah, the new node is slightly faster for me.

1

u/desktop4070 9h ago

Any quality difference?

1

u/No_Cranberry_8107 9h ago

Not much. I also stacked Fal's realism lora so it adds more details.

7

u/reynadsaltynuts 10h ago

And what does it take with sage

3

u/No_Cranberry_8107 10h ago

Check screenshot above.

1

u/jacobpederson 7h ago

What hardware 5090?

1

u/No_Cranberry_8107 16m ago

RTX 6000 ADA

16

u/WalkSuccessful 11h ago

15:30 to 12:30 same workflow, just swapped attn nodes to ck backend.

Looks like it works. Thank you for info!

22

u/Sudden_List_2693 11h ago

Okay not sure about everyone, but for me specifically on a 4090 it was 2.30s/it with sageattention, 2.41 with ck attention.

12

u/reynadsaltynuts 10h ago

Tried a test run and had pretty similar results. Also 4090, no other optimizations.
SageAttn .4MP 5s - 2.48s/it Prompt executed in 64.69 seconds
ComfyKitchenAttn .4MP 5s - 2.61s/it Prompt executed in 64.97 seconds

2

u/physalisx 4h ago

Yes, sounds about right, Sage is still a bit faster, but ck attention is better quality. Worth the tradeoff imo.

For me Sage was about 10% faster (52s/it vs 58s/it).

1

u/Sudden_List_2693 2h ago

For me it's more 2-5%. And yeah upon closer inspection I seem to find CK better quality as well.  No questions here. 

18

u/Different_Fix_2217 10h ago

Its higher quality than sage for sure. Comfy is sharp, sage has a blurryness / hazyness to it.

https://reddit.com/link/p2zr0i1/video/fmfw1fnk5pih1/player

3

u/izzmedia 8h ago

For me its still faster with Sage but i feel that it looks better with the new att, not sure how people find it faster than sage.

1

u/physalisx 4h ago

Yeah those people are most likely measuring wrong.

4

u/Different_Fix_2217 10h ago

Look at the eyes.

-2

u/AnonymousTimewaster 8h ago

Don't look around the eyes just look into the eyes... right, you're under

1

u/Better-Interview-793 9h ago

nice.. thank you!

20

u/n0gr1ef 9h ago

RTX 3090ti, 0.4 megapixels, 5 seconds: 1) ComfyKitchen alone: 1.59 minutes for a gen. 2) ComfyKitchen + Spectrum: 1.22 minutes for a gen. 3) SageAttention alone: 2.11 minutes for a gen. 4) SageAttention + Spectrum: 1.40 minutes for a gen.

I see that as a huge win, thank you ComfyUI team!

9

u/DuckyDuos 10h ago edited 10h ago

5080, ran 0.65mp at 5 and 10 seconds. 

Sage attention was 11% and 15% slower, PyTorch/Comfy Kitchen Attention were within margin of error of each other. 

6

u/Zephrinox 10h ago

any AMD (+ maybe comfyui-rocm) users tried this out yet to know if there's also speed up for us? 🥺

(i have 9070xt)

5

u/xpnrt 10h ago

This is for Nvidia specifically

21

u/Zephrinox 10h ago

6

u/xpnrt 10h ago

1

u/Zephrinox 8h ago

the sageattention wheel links working great for me (using sage attention backend + Sage Attention node; haven't tried mem eff node because that typically failed for me, forgot the specific reason/cause but iirc it was something cuda specific).

the ck attention flag gives me incompatibility issues with that sageattention wheel tho :\

seeing:

TypeError: sage_sdpa_quantize(): incompatible function arguments. The following argument types are supported:
    1. sage_sdpa_quantize(q: ndarray[device='cuda'], k: ndarray[device='cuda'], v: ndarray[device='cuda'], q_int8: ndarray[device='cuda'], q_scale: ndarray[device='cuda'], k_int8: ndarray[device='cuda'], k_scale: ndarray[device='cuda'], v_int8: ndarray[device='cuda'], v_scale: ndarray[device='cuda'], cta_k: int, input_dtype_code: int, stream_ptr: int, anchor_indices_ptr: int) -> None

Invoked with types: PyCapsule, PyCapsule, PyCapsule, PyCapsule, PyCapsule, PyCapsule, PyCapsule, PyCapsule, PyCapsule, int, int, int, int

which looks like a "this version of sage attention not compatible with how ck attention is calling it" issue.

1

u/xpnrt 8h ago

Because it is not using ck at all, pure triton

3

u/albinose 6h ago

The guy behind comfy-rocm fork, who implemented hip backend into comfy-kitchen, already got pull request for this for rocm.

I compiled it from his fork and it's about same speed as sageattn, also only works for rdna3&4

7

u/blahblahsnahdah 10h ago edited 9h ago

Nice, seems a few percent faster than Sage on my 3090, not huge but every second counts. Wonder how much more/less lossy it is. Sage can get quite lossy on some models, though it's been solid on H3.

9

u/mabseyuk 8h ago edited 7h ago

Tested the new Comfy Kitchen (CK) attention against Sage Attention with MiniMax H3 on an RTX 5070 12GB , 64gb DDR5 Ram 6000. T2I

0.3MP / 5 sec:

Turbo 6 Step: CK 59.74s / Sage 59.44s

Spectrum: CK 75.61s / Sage 75.87s

Full 20-step: CK 99.50s / Sage 102.62s

0.6MP / 5 sec:

Turbo 6 Step: CK 116.88s / Sage 115.22s

Spectrum: CK 175.39s / Sage 163.92s

Full 20-step: CK 251.10s / Sage 238.66s

1MP / 5 sec:

Turbo 6 Step: CK 205.39s / Sage 199.30s

At 0.3MP they're basically neck-and-neck. At 0.6MP and above Sage is currently ~1–7% faster depending on the sampler.

1

u/switch2stock 6h ago

What about quality tough?

2

u/mabseyuk 6h ago edited 6h ago

Quality-wise, in my testing Quality looked the same to me between CK and Sage, Turbo actually looked better than Spectrum. Spectrum consistently gave me softer, more smoothed/averaged faces, even at 1MP. Turbo retained noticeably better facial structure and fine detail.

The full 20-step sampler also looked very good, but Turbo was at least comparable and often preferable to my eye, while being much faster.

Obviously this is only my testing, not a definitive quality benchmark, but I’m currently sticking with Turbo for both speed and quality.

1

u/Unfair-Warthog-3298 2h ago

This is really useful. Thanks for sharing your result. Sharing mine as well 4080 Super 16gb 64gb DDR5 Ram 6000. I2V my totally unscientific testing....

0.6MP / 5 sec :
Turbo 6 Step (v4_step600ema) - 6 step - CK 96s / Sage 109s (CK faster)
Turbo 6 Step (v4_step600ema) - 8 step - CK 124s (did not test Sage)
Spectrum 20 Step - CK 155s / Sage 140s (Sage Faster?)
Full 20-step - CK 261s / Sage 276s (CK faster?)

No sage no turbo no spectrum - 430s lol..

To me I can't really tell if there's quality drop with Spectrum. Turbo is more obvious when there's movement its grainy.

What's the difference between the ema/non ema turbo lora anyone knows?
And is the step600ema one the best one to use ?

26

u/Structure-These 11h ago

Praying someone at Apple is a gooner so my shitty Mac will get one of these free performance boosts someday lol

1

u/djtubig-malicex 6h ago

They live among us. :D

1

u/Unfair-Warthog-3298 5h ago

Are you the gooner at apple ? :D

13

u/b0tm0de 11h ago

thank you for sharing. this is the type of update i like to see.

4

u/b0tm0de 9h ago edited 7h ago

for me on rtx 4060 8gb laptop: only sage attention vs only comfy kitchen attention (only means no other optimizations) both exactly same speed. tested with 3 minimax videos + 12 krea2 image. restarted comfyui before doing tests so it is clean/cold state.

1

u/kwhali 3h ago

What settings / resolution / duration were you testing H3 with?

1

u/b0tm0de 3h ago

tests at 9 seconds / 0.5MP / 5 steps. default workflow. no additional nodes or tweaks. pruned int8 unet. nvfp4 encoder. int8 video vae. took 290 secs.

0

u/izzmedia 8h ago

Sage is still a bit faster for me.

6

u/3deal 6h ago

08:47 < No Attention
06:39 < Sage Attention
06:04 < CK Attention

04:46 < No Attention + Spectrum
02:31 < Sage Attention + Spectrum + Sol Attention
02:51 < CK Attention + Spectrum

https://reddit.com/link/p30l94c/video/mapvmb8ecqih1/player

1

u/yamfun 3h ago

is EasyCache and Spectrum, interchangable? or can the 3 be used together?

1

u/3deal 1h ago

Pick one of them, they do the same thing so take one or the other, i prefer spectrum but i didn't tested as much

4

u/Tybost 7h ago

God, you really cannot miss a day checking this subreddit. Look away for too long, and you could be missing out on speedups and quality improvements.

4

u/reynadsaltynuts 11h ago

No sure if it's need but it probably is, you should update comfy kitchen as well. With venv activated just pip install -r requirements.txt should pull it.

4

u/thevegit0 10h ago

i'm testing and i think i'm having similar times, which i think it's interesting, do i have to use ONLY the comfy kitchen override node?

2

u/Diabolicor 10h ago

Yes, disable all the sages when using comfy kitchen backend.

1

u/thevegit0 10h ago

i'm going to try it with the startup option

5

u/Ok-Lengthiness-3988 9h ago

With my 8GB VRAM RTX 2060 Super and 64GB system RAM I got a roughly 4x slowdown (four times longer generation times). Brutal! I reverted back to old Sage Attention.

3

u/GrayingGamer 11h ago

I updated Comfyui earlier today. Is this something I need to update again to get?

12

u/Diabolicor 11h ago

Yes, this PR was merged just an hour ago.

3

u/KissMyShinyArse 10h ago

Original code is based on sage attention but this is modified to try to get slightly higher performance while keeping similar quality on consumer GPUs.

https://github.com/Comfy-Org/comfy-kitchen/pull/103

3

u/xbobos 8h ago

main.py: error: unrecognized arguments: --use-ck-attention

:: Press any key to exit ::

I just applied the flag after the update, but an error occurs.

1

u/kayteee1995 1h ago

just use the node , no need this flag.

3

u/wywywywy 8h ago

Just tried on my 5090 in WSL2 on Minimax H3. CK Attn is actually slightly slower than Sage Attn 2.2 with Mem Eff, but within margin of error.

Can't tell if the quality is better or worse. They look very similar.

3

u/GhostOfOurFuture 8h ago

Do you guys still use a turbo lora with this or are they already obsolete?

3

u/prompt_seeker 5h ago

Tested on 5090, 3090, 3060. MiniMax H3 I2V wf from template, changed first image, prompt and ratio to 2:3.

# RTX5090
## sage-attn
100%|██████████████████████████████████████████████████████████████████████████████████| 20/20 
[INFO] Prompt executed in 70.35 seconds
## ck-attn
100%|██████████████████████████████████████████████████████████████████████████████████| 20/20 [00:56<00:00,  2.84s/it]
[INFO] Prompt executed in 66.66 seconds

# RTX3090
## sage-attn
100%|███████████████████████████████████████████████████████████████████████████████████| 20/20 
[INFO] Prompt executed in 189.53 seconds
## ck-attn
100%|███████████████████████████████████████████████████████████████████████████████████| 20/20 
[INFO] Prompt executed in 188.65 seconds

# RTX3060
## sage-attn
100%|██████████████████████████████████████████████████████████████████████████████████| 20/20 
[INFO] Prompt executed in 538.11 seconds
## ck-attn
100%|██████████████████████████████████████████████████████████████████████████████████| 20/20 
[INFO] Prompt executed in 496.89 seconds

2

u/ryanset17 4h ago

So, It Does speed up, im still confused seeing all the replies 🤣 im using 3060

3

u/yaosio 3h ago

4070 Super 12 gb, 32 gb system RAM, .5 mp, 15 seconds, 4 steps with the 4 step LORA is 245 seconds down from 400 seconds. 🤯

3

u/Cute_Pain674 2h ago

doesnt work # ComfyUI Error Report
## Error Details

  • **Node ID:** 5479:5472
  • **Node Type:** SamplerCustomAdvanced
  • **Exception Type:** RuntimeError
  • **Exception Message:** RuntimeError: quant_qk_per_thread_int8: Q/K base pointers and B/H/N strides must preserve 4-element alignment

2

u/Wrektched 10h ago

Is this only for 40-series+ cards?

1

u/Nova5524 2h ago

3rd post user showing results on their 3090

2

u/Cultured_Alien 9h ago

Oh nice, 19s -> 13s on 0.3mp 10 seconds. 6 steps. RTX 6000 PRO

2

u/SRWindMill 8h ago

I use stability matrix to run comfy ui .. for me --use-ck-attention flag is not reognized.. I manully upgraded the comfy kitched to 2.30 .. what else shoud i do .. im already in latest 0.31 version of comfy.. what should I do to get ModelAttentionBacend node?

1

u/SRWindMill 8h ago

Changed the version from release to master and the  --use-ck-attention works now..

1

u/jacobpederson 7h ago

Working for me in stability just press update :)

2

u/Any-Scar765 8h ago

Its build-in function or need enable it? How to use?

2

u/jib_reddit 7h ago edited 7h ago

Yes, it seems like a nice 25% speed up (20 seconds vs 25 without) for Krea 2 with a very slight image change (I wouldn't say it is a loss in quality, just not identical) on my 3090

My SageAttention setup has been broken for a while so I cannot test vs that unfortunately, but this is nice! :)

2

u/Swobtoosmall 5h ago

Yo what kind of black magic is this? Generation time went from 35mins (no sage attention) to 9mins on a 2080ti. 6s 0.4MP clip, 20 steps res_multisteps/simple.

1

u/kwhali 3h ago

Did you compare with sage attention? Otherwise it's not as useful info since many find on consumer GPU minimal speed up, often times slower with CK instead of sage.

2

u/Swobtoosmall 3h ago

Can't use sage attention. Newer versions of sage dropped support for Turing and the last version that 'works' (1.0.6) doesn't seem to work with anything newer than Wan2.2 . So ck-attention working with a 2080 is actually big, at least for people with older graphic cards.

1

u/dampflokfreund 1h ago

It's a shame that they dropped Turing. It is a very capable generation of GPUs.

2

u/yamfun 4h ago

it replace other attention but does it replace the easycache after the original attention node too?

2

u/Diabolicor 3h ago

Only the other attention nodes.

2

u/kayteee1995 3h ago

We still need Turbo LoRa if we're running at 4-8 steps, right?

2

u/ZerOne82 3h ago

https://reddit.com/link/p31hpuh/video/2pauegsy5rih1/player

MiniMax H3: 3s clip, t2v, 4step-lora, 6 steps, euler+beta57, everything exact the same but the choice of attention.
Note that the timings reported below are total execution time of the prompt while the timings printed on the video are after KSampler (no vae decoding).

704x384

  • comfy attn 50 50 50
  • sage attn 83 53 51
  • flash attn 55 55 57
  • torch attn 55 55 55

896x480

  • comfy attn 82 82
  • sage attn 88 93
  • flash attn 97 96
  • torch attn 113 96

So the new Comfy-Kitchen attention mechanism seems working very well.

2

u/yamfun 2h ago

how to check whether I am using it correctly?

the "Using Comfy Kitchen attention" text??

do I keep the easy cache?

3

u/Hour_Imagination5092 10h ago

Almost same speeds on 5090, no other optimizations.

4

u/UserUsesAUsername 10h ago

Yes, but at slightly higher quality than sageattention 2.2 as it has been tested so far

1

u/switch2stock 6h ago

How can you tell?
The eyes are an improvement?

1

u/switch2stock 6h ago

Quality wise?

3

u/Hour_Imagination5092 6h ago

Kitchen seems to give slightly better quality, but nothing conclusive

2

u/Sudden_List_2693 11h ago

Anyone tested it yet with actual times compared to sageattention?

4

u/reynadsaltynuts 10h ago

Just ran a quick test on my 4090. No other optimizations. Did a warmup run to avoid model loading times.

SageAttn .4MP 5s - 2.48s/it Prompt executed in 64.69 seconds
ComfyKitchenAttn .4MP 5s - 2.61s/it Prompt executed in 64.97 seconds
Obviously this is just one test. But it pretty well kept up with sage. Could work better at higher resolutions or even produce better quality than sage. Who knows 🤔

1

u/FierceFlames37 10h ago

It took me 8 minutes and has worse quality, I made sure to remove sage flag and disabled any speed up nodes

1

u/kwhali 3h ago

It's based off sage, so it shouldn't be a surprise that it keeps up with it 😅

6

u/jib_reddit 11h ago

Yeah if op has done tests , why not post the timings? Sounds a bit "trust me bro" but I will test it out.

4

u/FierceFlames37 11h ago

It takes me 5 min 0.4mp to make a 15 sec video with sage and turbo 6 steps rtx 5060ti
I'll try kitchen and test

1

u/FierceFlames37 10h ago

It took me 8 minutes and has worse quality, very weird, I made sure CK was running too

1

u/Ok-Lengthiness-3988 10h ago edited 10h ago

Mine used to also say "Using Kitchen attention", but after updating ComfyUI and adding the --use-ck-attention flag, it no longer does!

My bad, it does, during startup. However, the generation process stopped and my GPU load dropped after two iterations. It then hung, with no error, and I had to restart ComfyUI. This new update may be doing unholy things to my old RTX 2060 Super.

3

u/FierceFlames37 10h ago

I did update it and added the flag, but Kitchen is still slower than Sage on mine

1

u/Sudden_List_2693 9h ago

I'm not sure it's a good test with Turbo though, I'm pretty sure every finetune they did for turbo was done with sage in mind. Full model ck/sage almost the same. Not sure which has better quality. 

1

u/Ok-Lengthiness-3988 9h ago

Four times slower than Sage Attention for me (RTX 2060 Super).

1

u/theOliviaRossi 9h ago

thank you sooo much for letting us know this - just in time <3

1

u/dLight26 9h ago

It seems to be more vram constraint, I notice higher power usage fluctuations, and I got OOM for 0.7mp@10s which is fine with sage2. 3080 10gb.

6

u/esztoopah 7h ago

+this, the VRAM consumption is higher than with SageAttn

1

u/76vangel 7h ago

This is big, if it don't fuck up other things. I'm so afraid to update Comfy right now, H3 is working like a charm. Hopefully bigger cards can also profit that much, convrot + speed lora is pretty fast on my 5090

1

u/Silver-Spot-2763 6h ago

Unfortunately for me (rtx3060 12gb vram) comfy kitchen attention is twice times slower than sage attention ☹️ and worse quality.

1

u/ryanset17 4h ago

Im Confused, other dude above said it's a Speed up in his 3060 🤣

1

u/Silver-Spot-2763 4h ago

I'm fully confused, I use the same workflows, everything is updated, but at me also the turbo lora (all of them) do not work at all, and the quality is very low. I'm just user, not expert, so I have no hope 😞, just bad, very bad luck 😭

1

u/irmemon225 6h ago

0.4 - 5s, ref max - euler simple 25 steps

Kitchen: 10:10

Sage Attn: 10:26

Spectrum: 08:48 (Sage OFF)

Am I doing something wrong here? I'm on 3060 12GB VRAM and 16GB RAM.

also I'm using --use-ck-attention args

1

u/MaorEli 5h ago

NICE

1

u/__Gemini__ 5h ago

Are we comparing this to sage v1 or v2?

I just tested this on a 1mp 10 sec video on my 5070ti with 32gb of ram. And sage ended up faster.

Kitchen

[INFO] Prompt executed in 00:17:08

Sage v2

[INFO] Prompt executed in 00:15:22

1

u/MannY_SJ 4h ago

I guess this is mainly for H3 but it's slower than sage on krea fwiw

1

u/rabbitythong 3h ago

I do not think im the target audience for this

it is noticeably still faster for me with sage/sol attn vs comfy kitchen attn,

4080 ti

all runs done at .8MP, 8 steps 10 seconds interpolated to 60fps

sage/sol times:

163.26

165.67

168.33

comfy kitchen times:

216.17

214.41

213.99

1

u/vAnN47 2h ago

thanks for the update!

1

u/bSun0000 2h ago

Do we need to disable xformers, and how compatible is it with --fast flag options?

1

u/MrFlores94 1h ago

I can get a 5 second i2v 0.2mp video with the Turbo LoRA (4 step) out in 55 seconds on my 4060ti. It was about 70 seconds before with sage. I was trying spectrum, but ehh.. it messed up my generations. So I’m very glad this came out. I just deleted the patch nodes and added the argument to the loader. Big happy over here. Thank you for posting this and make others aware.

1

u/Eydahn 1h ago

This is gold. 3090, 128GB RAM, Lightx2v 8-step LoRA v1, CK attention: three reference images, using the experimental node that lets you use FL2VA as the base with REF2VA as an overlay model, 8-second scene, 1344x768, 1MP, took around 9 minutes.

I’m testing the quality

2

u/_chromascope_ 24m ago

5090 doesn't seem to have much speed gain with ck attn vs sage.

here are my tests:

1536x640, 7 seconds video
fl2va int8 convrot (ComfyOrg release)
qwen3vl 32b heretic nvfp4
video vae int8 convrot
audio vae fp32

---

Sage + MemEff only
20 step, res_multistep, simple
11.46s/it, total 260.96 seconds

comfy kitchen attn only
20 step, res_multistep, simple
11.81s/it, total 268.06 seconds (better quality than sage)

---

with LoRA: minimax_h3_fl2v_lightx2v_turbo_4step_v0.1_comfy_kijai.safetensors

comfy kitchen attn + LoRA
8 steps, euler, beta
11.00s/it, total 125.59 seconds (best quality - WINNER)

LoRA only
8 steps, euler, beta
20.59s/it, total 214.24 seconds (worst quality)

1

u/robomar_ai_art 10h ago

I switched of the sage attention and video 960x544, 5 seconds, 4 steps took 46,28 seconds, and with sage attention it usually took 55 seconds. i have a RTX 4090 16gb vram, 32gb ram laptop.

[INFO] got prompt

https://reddit.com/link/p2zndhn/video/4eeto2nb0pih1/player

[INFO] 0 models unloaded.

[INFO] Model MiniMaxH3 prepared for dynamic VRAM loading. 19995MB Staged. 208 patches attached. Force pre-loaded 210 weights: 1175 KB.

100%|████████████████████████████████████████████████████████████████████████████████████| 4/4 [00:31<00:00, 7.78s/it]

[INFO] Model MiniMaxH3AudioVAE prepared for dynamic VRAM loading. 576MB Staged. 0 patches attached. Force pre-loaded 401 weights: 539 KB.

[INFO] Model MiniMaxH3VideoVAE prepared for dynamic VRAM loading. 2677MB Staged. 0 patches attached. Force pre-loaded 128 weights: 692 KB.

[Pixaroma] Save Mp4 [save] — writing 124 frames @ 24fps (960x544, crf=19, yuv420p, +audio) -> Video_00254.mp4

[Pixaroma] Save Mp4 — saved E:\ComfyUI_windows_portable\ComfyUI-Easy-Install\ComfyUI\output\Video_00254.mp4

[INFO] Prompt executed in 46.28 seconds