⚠️ The sm75 backend of this project has been merged into sdli1995's upstream repository. This repository will only be updated after future breaking updates.

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dlssg_sm75 v1.0 — Real DLSS Frame Generation on 20-series (Turing / sm_75)

2026-09-09, verified on real hardware: RTX 2060 Max-Q + The Witcher 3 next-gen (DX12). The in-game frame-generation toggle can be turned on, the backend installs successfully (backend_install status:0), and the log shows no bridge_error.

Chinese version: 部署说明.md. Byte-level change list vs. the originals: 改动说明.md (Chinese).

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1. What this is

It uses the stock nvngx_dlssg 310.1 as the runtime together with a purpose-built sm75 backend: the backend replaces all 72 kernels embedded in 310.1 (originally sm_89 / sm_120 only) with sm_75 cubin / PTX produced by ptxas, then rewrites the architecture gate and the reported architecture to values that Turing accepts. Three components, three jobs:

File	Role	What changed
version.dll	stock dlssg_for_sm86 proxy	only 10 bytes differ from the original (all inside the embedded backend resource): 5× SM gate cmp …,0x56 → 0x4B; 3× arch report 0x170 → 0x190 (Ada); 2× requirements bridge 0x170 → 0x160 (the real Turing value)
dinput8.dll	injection vehicle (the game statically imports it, so it is always loaded)	intercepts nvapi_QueryInterface: for callers outside the exclusion list it forces GPU_GetArchInfo to Ada 0x190 and stubs the Ada-only D3D12_SetRawScgPriority to success; it then overrides the runtime's GetFeatureRequirements exports to "supported" (Flags=0, arch 0xC0) and NOPs 3 flag sites
runtime\sm75_backend.dll	sm75 backend (rebuilt)	144 resources = 72× sm_75 cubin + 72× sm_75 PTX; gate / report / bridge patches identical to those in version.dll
runtime\nvngx_dlssg.dll	runtime	unmodified, stock 310.1

version.dll and runtime\sm75_backend.dll are two independent paths carrying the same patch set. This package uses Pinned + [Backends] to load the external backend (see the INI), so the file actually in effect is runtime\sm75_backend.dll.

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2. Package contents (SHA256)

Path	Bytes	SHA256
version.dll	10522624	2D7DC46E3B81BB29CB698A2B2EA3A4EF2DD3BCB5C90E86A47E035DF4E1EDAA37
dinput8.dll	163840	948CADAEAFC24A0CDA1AB541BBC06A4A20DA28A4835646CEA9F5701F4892A210
dlssg_sm86.ini	847	8AC5CF8655B3E68C3B44D8039AA43DC11A5E82DAD316B67FD8A5850EDBF36DB7
runtime\nvngx_dlssg.dll	7596088	C989C0EBD9CD21DBF3DB0BECD857AA1F218068D94DA371D924331A6F0FB97525
runtime\sm75_backend.dll	2667520	D96FD76499E2EBE2926E7EA8266375E528F1F746D7F4D2B97AAA01D0C1996038

The [Backends] key must equal the actual SHA256 of runtime\nvngx_dlssg.dll (i.e. c989c0eb… in the table above). If you swap the runtime, you must update this key too, otherwise the backend will not be loaded.

The dlssg_sm86.ini shipped in this package is the exact byte-for-byte working copy from the test machine (comments included). The comment above its [Compatibility] section — "Auto on a forced route -> PTX … Try Cubin later" — is out of date: the value actually in effect is KernelImage=Cubin, so do not "fix" it to match the comment.

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3. Installation

1. Close the game.
2. Copy this folder's version.dll, dinput8.dll, dlssg_sm86.ini and the whole runtime\ directory into the directory that holds the actual rendering EXE (Witcher 3 next-gen: ...\The Witcher 3\bin\x64_dx12\), overwriting files with the same name.
3. Clear the old cache: empty %LOCALAPPDATA%\DlssgSm86\bundles\. (A backend bundle left behind by an older package breaks the SHA matching, so this is mandatory.)
4. Leave the game's own nvngx_dlssg.dll alone — the load request is redirected by version.dll to runtime\nvngx_dlssg.dll. If another mod pack (e.g. an FSR3 build) already replaced it, just leave it as it is.
5. Launch the game → open DLSS Frame Generation in the display / graphics settings.

Requirements: Windows x64 + a DLSS 3 capable driver + an RTX 20-series (Turing) GPU.

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4. Verifying that it really works

dlssg_sm86\logs\loader_<pid>.jsonl

"event":"configuration"   → "runtime_mode":"pinned", "kernel_image_requested":"cubin"
"event":"backend_install" → "status":0, "backend":"...\runtime\sm75_backend.dll"

dlssg_sm86\logs\backend_<pid>.jsonl

"event":"mfg_capability" → "changed":true, "reported_max":3      ← multi-frame capability accepted

bridge_error or Embedded SM86 kernel missing must not appear.

dlssg_sm75_inject.log (in the same directory as the EXE)

[inject] GetArchInfo arch 0x160 -> 0x190 (Ada)
[inject] GetFeatureRequirements -> success (flags 0, arch 0xC0)
[inject] QI(D3D12_SetRawScgPriority) -> stub

In game: the frame-generation toggle switches on and the frame rate clearly goes up.

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5. Known behavior / limitations

• The backend log may contain one entry {"event":"kernel_create", "source_rva":"0xda7a0000", "routed":false, "status":-14} — that is one of nvngx's own empty-blob probe calls (blob=NULL); the backend is not involved and it is harmless.
• Maximum generated frames: 3 (MaxGeneratedFrames=3).
• Only validated with Witcher 3 DX12. Other DLSS-FG capable games should work in principle, but are untested.
• KernelImage=Cubin is the validated path; switching it to Auto falls back to PTX (driver JIT) and is meant for troubleshooting only.

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6. Uninstallation

Delete version.dll, dinput8.dll, dlssg_sm86.ini, runtime\, dlssg_sm86\ and dlssg_sm75_inject.log. version.dll is the stock proxy file, so Steam's "verify integrity of game files" will restore the game's own copy.

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7. Sources

• Blueprint: dlssg_for_sm86-main (the stock version.dll proxy + backend resources).
• Architecture spoofing approach: dlssg-to-fsr3 (nvapi GPU_GetArchInfo reporting Ada).
• nvngx_dlssg.dll is an original NVIDIA runtime file, copyright NVIDIA; this package is for local testing only.