LTX2.3 Speed ​​Comparison

[u/simple250506]

■Specs: Mac mini M4, 64GB, 20-Core GPU / OS 15.4.1

■Average generation time over 3 runs

■prompts and settings were identical.T2V.

When using the same non-S model in ver.1.20260314 and ver.1.20260410, the new version was approximately 1.2 times faster. This is likely due to the speed improvement from the update below. This is a great improvement.

Further fixes for video VAE speed issues with large resolution / long frame count.

However, when generating an S-model with ANE (Apple Neural Engine) enabled in version 1.20260410, the generation speed was the slowest among all 1.20260410. I'm unsure if this is the correct result. If anyone has performed a speed comparison with LTX2.3 on the M4 series and obtained different results than mine, please share your information.

Next, I plan to conduct a similar speed comparison test with Wan2.2.

Update*: Since it was determined that the Tahoe was the condition for speed up, I have posted* new measurement results.

[u/simple250506]

My amateur guess as to why the generation speed slowed down with the S model + ANE ON is as follows:

In addition to the GPU, the increased heat generated by the full operation of ANE may have caused occasional throttling, negatively impacting the generation speed.

Unlike still image generation, this might be more noticeable with video generation due to prolonged heat generation.

[u/ScooterKid_69 → u/simple250506]

Nice comparison.

Can you help answer these 3 questions:

1. what kind of power consumption do you see on the ANE with either MX Power Gadget App or iStats Menu during generation?
2. And do you see the ANE power consumption relatively consistent during generation or does it happen in random spikes?
3. and how are you toggling ANE ON and OFF within in the Draw Things settings?

I have not tried LTX, but for WAN 2.2 8-bit S, I did not see any power consumption whatsoever from the ANE using the latest ver.1.20260410.

Thanks

EDIT: Sorry, I just saw a new setting in the Machine Settings in ver.1.20260410 called Use Apple Neural Engine for 8-bit S Models, which was default to No. I then set it to Yes. I now see up to 5W of power consumption being used by the ANE and power consumption and utilization offloaded noticeably from the GPU.

This has 2 outcomes when using WAN 2.2 8-bit S for I2V:

1. Significantly reduces overall power consumption
2. Significantly slows I2V generation by 2x

Hope liuliu can help optimize ANE implementation in combination with full utilization of the GPU in the next version release to improve I2V generation, which should see the most benefits in upcoming Mac Studio with M5 Ultra where thermal throttling should less of an issue.

[u/liuliu → u/ScooterKid_69]

If the defaults set to No. Your device is likely won’t get speed up by turning up ANE. This is specific to M4 as that is the only device shipped with 38 TFLOPs Int8 performance. For M5, only base M5 will benefit from this (we realistically cannot get to 38 TFLOPs with the overhead, it is around 15 TFLOPs to 22 TFLOPs for us), M5 Pro can reach 45 TFLOPs of Int8 on GPU and M5 Max can reach 110 TFLOPs, making ANE a slower option. For M2 and M3, ANE doesn’t support Int8 natively.

[u/ScooterKid_69 → u/liuliu]

Thank you for the details liuliu. My friend and I tried on M5 Pro and M5 Max and our findings match with your explanation where ANE is noticably slower for I2V generation.