d4r/docs/windows-k-performance.md

Windows K performance work

Current optimization pass: strict DS exchange, 1080p and 1440p (2026-10-17)

After the position-layer barrier fix, the explicit gfx11 DS cross-half exchange passes the strict gate. kernels/common/wave32_exchange.h uses ds_bpermute with the current wave's lane XOR 16 instead of the volatile LDS array and its fences. No arithmetic, half rounding, weights or tensor layouts change. Windows gfx11 K selects it through D4R_WINDOWS_GFX11_DS_EXCHANGE; M retains its validated LDS path. The experimental builder retains explicit -LaneExchange lds|ds selection for comparisons.

Final CMake-built candidates, authentic private K model, synthetic 24-frame temporal cases, 25 frames/submit, 12 timing trials with three warmup trials excluded. Timestamps span Vulkan front, HIP network, Vulkan back and the CPU synchronization gaps; these are not network-only or game timings:

Output	Fixed LDS baseline	Strict DS candidate	Change
1920x1080	2286.4 us	1811.9 us	20.8% faster
2560x1440	3587.7 us	2885.4 us	19.6% faster

All five frame products match baseline hashes exactly at both sizes (120 products per case). Evidence: build/k-ds-cmake-1080-final-v1/summary.json, build/k-ds-cmake-1440-final-v1/summary.json. Independent manual-build comparisons also pass, at 1808.7/2877.0 us. CMake/manual code objects differ as artifacts; the actual CMake objects receive their own full output checks. Final native objects are under build/k-ds-native-cmake-v2/. The v1 CMake candidate is rejected: an intermediate CMake regex overwrote the captured per-source flags; the capture is now saved immediately, preserving CU and QKV-split flags.

Further experiments retained no reliable additional gain: position token counts 1/2/4, shared V values, SPIR-V size optimization of input/output, and all-WGP scheduling. Every compared candidate here is exact; many are slower. WGP measured 2862.3 vs 2847.2 us at 1440p and 1795.7 vs 1813.9 at 1080p, within small run-to-run differences and inconsistent across sizes. It is not promoted. Evidence is under build/k-hip-opt-sweep-v1/, k-hip-opt-ds-share-v1/, k-hip-opt-stage-mt1-v1/, and k-ds-wgp-*-v1/.

The HIP standalone engine/model is still separate from the package's NGX feature-1 path. The package can use the same faster K layer objects through its existing ZLUDA/NGX route; that route requires separate whole-frame validation and CPU interop timing. Linux targets of 1.5/2.47 ms remain unmet. Further substantial work would require the Vulkan front/output stages or the cross-API synchronization path; it is outside this bounded optimization pass. Broader K temporal/reference-quality and production-adapter work remains open.

The final v14 ZIP's loader/INI passes 64 exact synthetic NGX K frames per size in control/candidate/candidate/control order. CPU interop medians: 1080p 3.900 -> 3.3915 ms (13.0%); 1440p 5.4015 -> 4.820 ms (10.8%). Unlike the standalone timestamp table, these include CPU API/copy/synchronization/NGX overhead. They are not game FPS. Evidence: build/k-ds-local-v14-{1080,1440}-v1/summary.json. An earlier legacy 1080p run overlaps build activity; its exactness evidence remains valid, but the packaged player runs supersede its timings.

Stability diagnostic: build/k-ds-repeat-node-final-v1.log, 300 frozen-input rounds x 8 window phases (2,400 launches), zero output-hash mismatches. Its individually instrumented network nodes total 1,926.04 us at 1440p. That instrumentation is separate from accepted frame timings. Raw readbacks created by this pass were checked against recorded hashes and pruned to recover 5.05 GiB; logs, summaries, hashes and final previews remain. Cleanup inventory: build/k-opt-readback-cleanup-v1.json. No earlier artifacts were deleted.

Temporal isolation follow-up

The intermittent drift is not fixed or attributed to a specific layer. New benchmark_k_interop.py --reset-every-frame passes an explicit diagnostic option to the D3D12 harness, verifies its application and records it in the report. This mode does not represent normal temporal inference or game performance.

With the validated private CU output, 16 frames per run and four player runs:

Isolation	Exact evaluations	Evidence under build/
Reset every frame, ABBA input batching	64	k-player-reset-every-frame-1080-v1
All K network layers translated, CU output retained, temporal ABBA	64	k-player-translated-network-temporal-v2
All native K, unbatched identical controls	64	k-player-native-temporal-controls-v1
Native encoders only, translated decoders, temporal ABBA	64	k-player-native-encoders-temporal-v1
Translated encoders, native decoders only, temporal ABBA	64	k-player-native-decoders-temporal-v1
All native K and CU output, temporal ABBA rerun	64	k-player-native-temporal-abba-v2

Each row has an authoritative summary.json. Reset-every-frame also produces one identical output hash across all frames within each run. Thus accumulated state matters in the earlier failing case, but that alone does not establish a history implementation defect. The mixed native/translated cases do not isolate an individual layer, and the full native ABBA rerun passes after the earlier failure. Initialization, cache state, scheduling and arithmetic remain possible investigation targets; no one cause is demonstrated.

Diagnostic manifests select translated or native K layers while preserving the same object files, private CU output, dependencies and baseline. Runtime logs verify actual translated enc0/dec0 selection for the all-translated case. Those manifest variants remain private under build/k-network-*-native-output-cu-v1/ and build/k-translated-network-output-cu-v1/; no source kernel, runtime default, game or delivered ZIP was changed to use them. First translated-network fixture v1 failed before NGX because its setup command had a quoting error and did not create the selected directory. A native Python fixture setup corrected it; v2 passes. No security policy block or bypass occurred.

The reset diagnostic's timings are not normal K timings. Mixed/translated cases also are not proposed performance configurations. The full native rerun records CPU medians 3.018/2.9155 ms, unbatched/batched, but earlier drift still prevents promoting a default or claiming deterministic behavior. No GPU-time/Linux parity, image-quality or real-game speed conclusion follows from these isolation runs.

Latest: rejected kernel candidates and unresolved player temporal exactness

No new kernel or batching default is promoted. The current delivered ZIP remains v8 with batching off. The working tree adds an experimental [Interop] BatchInputCopies switch, default false, plus parser/environment tests and checker support. Missing/invalid values keep older unbatched behavior. CPU player-config tests pass; checker syntax parses. Exactness in the player performance fixture remains unresolved, so keep the switch false.

benchmark_k_interop.py --control-native DIR selects an explicit verified native baseline. --player-config stages dependencies and selects batching/native paths through actual INI. It preserves per-run player logs. --sequence controls or batches repeats identical settings to diagnose determinism. Failed comparisons record mismatching frame names and hashes; they do not receive accepted timing. compare_k_outputs.py measures preserved half-output differences without GPU work.

New private experiments, all artifacts retained and excluded from ZIPs:

• WGP scheduling for the existing native output override: 64 exact 1080p frames, with CU/WGP warmed CPU interop medians 3.048/3.0455 ms (no reliable gain). At 1440p the candidate failed the exact-output gate: five of 16 compared frames differ, 14,836 components, max absolute difference 0.00537109375; all values finite. Candidate rejected. Evidence: build/k-output-wgp-vs-cu-{1080,1440}-v1/ and 1440p mismatch-analysis.json.
• CU input override: recipe changes only eight round-to-zero idioms; no surface stores matched this LDR input variant. Four of 16 frames differ, 993 components, max absolute difference 0.00048828125; finite. Candidate rejected. Evidence: build/k-input-cu-vs-output-cu-1080-v1/mismatch-analysis.json.
• Legacy/environment mode with validated private CU output plus existing input batching: 128 exact frames across 1080p/1440p ABBA comparisons. Warmed CPU interop medians: 3.072/2.9305 ms at 1080p, 4.4605/4.3345 ms at 1440p, unbatched/batched. build/k-output-cu-batch-{1080,1440}-v1/summary.json.

Player-mode checks exposed an important limit to those narrow successful runs:

• In the baseline-kernel 16-frame ABBA run, both batched runs match first control exactly, but the final unbatched control differs in 15 frames, 38,472 components, max absolute difference 0.01318359375. This does not isolate a batching defect. build/k-batch-player-1080-v1/repeat-analysis.json.
• Four identical unbatched player runs of eight frames each pass all 32 exact frames. build/k-player-control-repeat-1080-v1/summary.json.
• A 16-frame player comparison using the validated private CU output differs between control and batched run in eight frames, 1,416 components, max absolute difference 0.00048828125. First difference is frame 8, with RGB differences spread across the image and unchanged alpha. Candidate is not accepted. build/k-batch-player-output-cu-1080-v1/difference-locations.json.

These results leave temporal determinism, arithmetic/initialization and ordering as investigation targets. They do not prove any one of those causes. The kernel candidates failed acceptance, but baseline drift prevents attributing every difference solely to a candidate. No relaxed tolerance was substituted for the exact gate. Private candidates, validated CU control and original runtime remain separate. No GPU-time/Linux parity or game-speed claim, game access, driver/GPU/ security change, commit or publication occurred.

Linux's reported 1.5 ms at 1080p and 2.47 ms at 1440p remain targets, not verified Windows results. The synthetic measurements below include CPU synchronization, format/array copies and NGX execution. They are not directly comparable to a GPU network-only timer or a game's frame time.

Reproducible interop comparison

tools/windows/benchmark_k_interop.py uses an existing private gfx1101 runtime and the native D3D12 harness. It runs control/batch/batch/control, with 16 frames per run and the first four excluded from timing. Every frame is read back; candidate output hashes must match the control frame for frame. The harness also rejects nonfinite or uniform outputs. No game is launched or modified.

Use the current installer core, not an older isolated NGX fixture:

python tools/windows/benchmark_k_interop.py `
  --probe build/windows-rdna4-therock-gfx1101/d4r_d3d12_dlss_probe.exe `
  --shim build/windows-rdna4-therock-gfx1101/d4r_nvngx.dll `
  --runtime build/got-k-test/work/package-gfx1101-current/d4r `
  --core build/driver-617.14-core-check/_nvngx.dll `
  --dlss build/got-k-test/isolated-sr/sr/nvngx_dlss.dll `
  --output build/k-new-benchmark --resolution 2560x1440

Paths above identify local ignored artifacts; provision matching artifacts on another machine. The runtime argument supplies HIP, ZLUDA, NVAPI, the gfx1101 pixel converter and native K objects. Output must be a new folder under build/. Each process has a 180-second limit. Reports retain executable/DLL hashes and native object hashes. --profile-stages adds CPU stage diagnostics; its timings include logging overhead and must be reported separately.

The harness otherwise defaults to half-resolution input. This runner explicitly sets nominal Quality input: 1280x720 for 1920x1080 output; 1706x960 for 2560x1440. Games can round the render width differently (GoT used 1712 at 1440p).

Evidence, RX 7700 XT, 2026-10-16

The 617.14 core SHA256 is 66767018c36b3bab46398dade3adf173daa3730fda75965689ea848c9bc4e79b; SR 310.9.1 matches the installer pin. Native K encoders are reported loaded in the captured stderr. Baseline RGBA16F inputs/output need no format conversion.

At 1706x960 to 2560x1440, pooled warmed CPU interop medians were 5.2615 ms control and 5.0800 ms batch. All 64 frame outputs passed and matched exactly between modes. Evidence: build/k-interop-batch-quality-1440-core617/summary.json. At 1280x720 to 1920x1080, the same check passed all 64 frames; pooled warmed medians were 3.5730 ms control and 3.3820 ms batch. Evidence: build/k-interop-batch-quality-1080-core617/summary.json. These short runs suggest only a small batching benefit; defaults remain unchanged. This does not establish image quality on realistic ray-traced/game content.

Earlier investigation runs used core 596.36 or stage profiling. Their artifacts are retained separately and are not the current-core baseline. Batched input copies alone do not establish Linux speed parity. Next optimization needs paired GPU kernel timings and an exact-output comparison, particularly for the native gfx11 kernels' Windows lane-exchange workaround and the translated texture stages.

Kernel experiments and GPU profile

The experiment builder now accepts an explicit gfx11/gfx12 target. gfx11 keeps its Windows LDS lane-exchange workaround and strict FP16 accumulation. Gfx12-only tiling/storage experiments are rejected on gfx11. Compiler arguments, target, object hash and ISA remain in the experiment output directory.

benchmark_k_interop.py --candidate-native DIR compares an experimental native folder against the existing runtime, using identical interop settings. Candidate runs must match every output file before their timing is accepted. No candidate is installed into the existing runtime or a game.

A strict enc1 ds_bpermute replacement failed exact temporal output comparison: eight of 16 frames differed, maximum absolute difference 0.00048828125. The fresh LDS control passed the same comparison. The DS source experiment was removed; its local artifacts remain under build/k-bpermute-strict-enc1-quality-1080/. Earlier non-strict experiments omitted D4R_K_FP16_BASELINE and cannot isolate shuffle behavior. The DS builtin also folded to v_permlanex16; explicit assembly was needed to test an actual DS instruction.

Enc1 WGP mode passed all 64 frame comparisons but showed no reliable speed gain: control/candidate pooled warmed CPU interop medians 3.5455 / 3.5865 ms. No default or package change. Evidence: build/k-enc1-wgp-quality-1080/summary.json.

--profile-kernels enables deferred GPU events with legacy-stream profiling explicitly allowed for this synthetic diagnostic. This changes stream dependencies and substantially raises CPU interop time; do not compare its wall times with the uninstrumented baseline. In the first control run, the last-four-sample GPU medians were approximately:

Stage	GPU ms
translated output hiluma_engine_output_depthreg_mvhi_ldr_max_v2_rel	0.820
native dec0	0.301
native enc0	0.293
native dec1	0.261
native enc1	0.213

All 32 instrumented frames passed exact output checks across control/candidate. Raw logs and per-run stage analysis are in build/k-enc1-wgp-gpu-profile-1080/gpu-stage-analysis.json. These are instrumented stage measurements, not an uninstrumented total. The translated output pass is the largest measured stage and is the next optimization target. The existing private texture recipe needs d4r_emit.exe, which is absent from the current workspace's tool/runtime/build directories. No Linux speed parity is claimed.

Offline emitter provisioning

The dependency checkout is now local under ignored external/ZLUDA, pinned to ee2f25a180099fa42f36b2346732e1f2470a03ad with this repository's Windows patches. LLVM is pinned to ff4dc1f7c9e1c64d4d69e40f4ed30c2280a96dfd plus the audited gfx1154 backport. Rust 1.98.1 and locked Cargo dependencies are provisioned locally. All four PTX helper variants built with TheRock's compiler. They have not yet been linked or exercised by the emitter. LLVM library compilation is in progress.

After the LLVM build succeeds, run:

./scripts/windows/build-zluda-windows.ps1 -EmitterOnly
./scripts/windows/build-native-texture.ps1 `
  -DlssDll build/got-k-test/isolated-sr/sr/nvngx_dlss.dll `
  -Kernel hiluma_engine_output_depthreg_mvhi_ldr_max_v2_rel `
  -HipRoot .tools/therock-10.2.0a20260929/_rocm_sdk_core `
  -ZludaRoot dist/zluda-windows-emitter -GpuArch gfx1101 `
  -OutputDirectory build/private-k-output-gfx1101

Emitter-only mode does not build or replace nvcuda.dll, NVAPI, or the tracing runtime. It writes the offline emitter and its local C++ DLL dependencies to a separate directory. The texture recipe resolves compiler tools from either the TheRock lib/llvm/bin layout or the HIP SDK bin layout; derived output must stay under ignored build/. Each extraction/compile operation has a 600-second limit. Output overrides remain unvalidated until full-frame comparison passes.

K native output override validated (2026-10-16)

LLVM completed all 2,322 library build steps. The offline emitter now builds and passes three gfx1101 compile fixtures (pattern, f16 reference MMA, f16 WMMA). The validated CUDA/NVAPI runtime was not rebuilt or replaced.

Two build compatibility fixes were required for TheRock's LLVM 24 frontend:

• Remove stale ThinLTO summaries after stripping unused HIP/LLVM globals.
• Assemble helper IR with the pinned LLVM 22 assembler. A small compatibility pass preserves float bit patterns, translates the dynamic denormal attribute to LLVM 22's equivalent, and drops optimization promises the older reader cannot express. It does not enable relaxed math. Five tests cover finite float widening across exponent boundaries, NaN payloads, half constants, double/string preservation and conservative attribute handling. End-to-end exact output checks below are the runtime gate.

The private native store override for hiluma_engine_output_depthreg_mvhi_ldr_max_v2_rel built for gfx1101. The PTX recipe replaced 13 formatted stores, four b32 stores and eight round-to-zero stores. The runtime log confirms the new native output module is loaded.

Paired control/candidate/control-order measurements (control, candidate, candidate, control), 16 frames per run, first four excluded:

Nominal Quality geometry	Control CPU interop ms	Candidate CPU interop ms
1280x720 to 1920x1080	3.791	3.440
1706x960 to 2560x1440	5.318	4.744

All 128 frame outputs were finite/nonuniform and matched control bytes exactly. These CPU measurements include synchronization and copies; they do not establish Linux GPU-time parity or game speed. No game was accessed.

A separate deferred-event diagnostic passed 32 additional exact frame checks. The output-stage GPU medians were 0.812/0.815 ms in the two controls and 0.535/0.532 ms in the two candidates. Legacy-stream events add dependencies; these instrumented stage measurements are not uninstrumented frame totals.

Private artifacts: build/private-k-output-gfx1101/ and combined build/k-output-native-gfx1101/. Evidence: build/k-output-native-quality-{1080,1440}/summary.json and build/k-output-native-gpu-profile-1080/output-stage-analysis.json. The override derives from the user's NVIDIA DLL and remains under ignored build/; it is not included in the previously delivered local ZIP. Other K input/output variants, game performance and automatic local override generation remain open.