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recommend("ltx25"): nf4 with block streaming for LTX-2.5 - #76

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TroyHernandez merged 2 commits into
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feat/recommend-ltx25
Oct 29, 2026
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TroyHernandez merged 2 commits into
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feat/recommend-ltx25

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recommend("ltx25") for LTX-2.5.

recommend("ltx") (LTX-2.3) prescribes streamed fp8 on 10-14 GB cards, and LTX-2.5 has no fp8 artifact. The new "ltx25" ladder is nf4 on every GPU tier:

Free VRAM Transformer Text encoder Cap
14 GB+ resident CPU 1280^2
7.5-14 GB vram - 4 GB resident, rest streamed GPU, streamed below 12 GB 768x512
below 7.5 GB CPU CPU 512^2
  • The result adds the ltx23_memory_profile() fields resident_gb, stream_text, split_text and resident_from.
  • Staging stays pinned on the GPU tiers. The 2x-pinned-set rule would unpin below ~58 GB and make block streaming slow; the host-RAM fields bound the footprint instead (measured 20.1 / 16.0 GB high-water on an 8 GB card).
  • recommend("ltx") and serve.R are unchanged.

Tests: full suite 1640 passed, 0 failed. Version 0.2.2.19.

LTX-2.5 has only the nf4 artifact, so the 10-14 GB fp8 tier of
recommend("ltx") pointed at nothing. The new ltx25 ladder is nf4 on
every GPU tier and carries the ltx23_memory_profile fields
(resident_gb, stream_text, split_text, resident_from). Staging stays
pinned on the GPU tiers. recommend("ltx") (LTX-2.3) is unchanged.
@TroyHernandez
TroyHernandez merged commit 9ecded1 into main Oct 29, 2026
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@TroyHernandez
TroyHernandez deleted the feat/recommend-ltx25 branch October 29, 2026 03:28
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