Remove game log backpressure and measure Windows K/M kernels

docs/windows-game.md

@@ -46,6 +46,18 @@ the GPU before returning it to D3D12. Only two diagnostic counters (8 bytes)
 are read by the CPU; image data remains in VRAM. Validation failures are
 reported explicitly. Disable this diagnostic when measuring production speed.
 
+`-ProfileStages` records CPU completion time for seven interop/NGX stages.
+The runner drains stdout/stderr concurrently as raw bytes; the earlier
+line-oriented PowerShell collector imposed large per-frame delays. The optional
+ZLUDA kernel profiler is for diagnostics only. Measurements and reproduction
+commands are in [windows-performance.md](windows-performance.md).
+
+Ordinary runs use OptiScaler info logging and suppress successful HIP/CUDA API
+messages. Errors, GPU identity, imports, frame records and native/translated
+kernel launches remain logged. `-VerboseRuntime` enables all API and frontend
+trace messages when investigating a failure. Numerical relaxation flags are
+cleared in the child process; FP16 rounding and subnormals stay enabled.
+
 Original files are backed up before replacement. Restore with:
 
 ```powershell

docs/windows-performance.md

@@ -0,0 +1,77 @@
+# Windows RDNA4 measurements
+
+Hardware: RX 9070 XT / gfx1201, Windows 11, display driver 32.0.31041.1004.
+Runtime: TheRock 10.2.0a20260929, HIP 7.17.26386; ZLUDA b0161a4 with
+`D4R_ZLUDA_WMMA=1`, FP8 widening, native FP8 disabled, f16 reference rounding.
+
+The optional profiler uses HIP events on the actual launch stream, including
+separate measurements of one-time weight preparation. It synchronizes each
+sampled launch and changes scheduling: these numbers are not application FPS.
+HIP occupancy predictions are not measured hardware occupancy. The native
+objects' actual wave32, LDS, VGPR/SGPR and spill counts are available in
+`llvm-readobj --notes` and can be attached to the JSON report. Memory bandwidth
+and WMMA utilization were not measured; no utilization is inferred from timing.
+
+The identical four-frame standalone D3D12/OptiScaler workloads output 512x288.
+Summing the measured main-kernel event times and dividing by four gives:
+
+| Preset | Fully translated, ms/frame | Native FP16-equivalent, ms/frame |
+| --- | ---: | ---: |
+| K | 157.745441 | 0.684675 |
+| M | 7.428538 | 1.566500 |
+
+Both rows include translated input/output tails. Native overrides cover all
+11 K layers and five M layers; M's tube layer executes six times per frame.
+M native and translated RGB are bit-exact, with max absolute/relative error 0.
+K native remains bit-exact against its independently validated native control;
+fully translated K has the previously documented arithmetic differences.
+All outputs are finite. These are reference-correct codegen settings, not
+measurements of a relaxed fast-math translated configuration.
+
+M's first profiled Evaluate includes about 0.9 seconds of host initialization;
+the four-sample CPU mean must not be treated as steady-state latency. Its
+median Evaluate host completion is 4.855 ms. GPU events and prep phases are
+reported separately in the raw JSON.
+
+The initial game runner used PowerShell line-oriented output redirection.
+It heavily throttled verbose stdout/stderr. The runner now concurrently drains
+raw byte streams using the same approach as the standalone diagnostics.
+
+| Silent Hill 2 stage, CPU mean | Initial capture, ms | Raw-byte capture with HIP profiler, ms |
+| --- | ---: | ---: |
+| Input fence wait | 5.641 | 0.833 |
+| Input conversion and CUDA array upload | 13.196 | 0.668 |
+| NGX Evaluate host call | 25.715 | 3.350 |
+| NGX all-stream completion | 1.846 | 0.033 |
+| Output CUDA array download | 4.288 | 0.167 |
+| Output conversion and shared fence signal | 1.500 | 0.033 |
+
+The first run additionally scanned every output (10.142 ms in that throttled
+capture); the kernel-profiling run disables that scan. Both use a temporary
+1280x720 window and current-frame VRAM interop. These are separate menu/game
+runs, not a controlled whole-game FPS comparison. No synchronization was
+removed to obtain the improvement. The raw-byte profiling run completed
+2345 K frames, with no d4r failure, CPU image copy or previous-frame output.
+
+Reproduce native or translated measurements with locally supplied NVIDIA DLLs
+at the repository root and the separately built profiling runtime:
+
+```powershell
+.\scripts\windows\profile-windows-rdna4.ps1 -Preset 11
+.\scripts\windows\profile-windows-rdna4.ps1 -Preset 11 -Translated
+.\scripts\windows\profile-windows-rdna4.ps1 -Preset 13
+.\scripts\windows\profile-windows-rdna4.ps1 -Preset 13 -Translated
+```
+
+`profile_report.py <results-directory> --output profile.json` summarizes raw
+CPU stages and every kernel's event time, launch geometry, registers, private
+memory, LDS and predicted blocks per multiprocessor. Add
+`--metadata-directory <directory-of-llvm-readobj-notes>` for native wave sizes
+and compiler spill counts. Reports and proprietary workload inputs remain local.
+
+Native FP8 is not the validated baseline and has no performance claim here.
+Replacing the exact per-MMA f16 rounding with f32 FP8 accumulation requires a
+new layer/reference validation; it is not justified by the observed CPU stalls.
+
+References: [HIP events](https://rocmdocs.amd.com/projects/HIP/en/develop/doxygen/html/group___event.html),
+[HIP occupancy API](https://rocm.docs.amd.com/projects/HIP/en/latest/doxygen/html/group___occupancy.html).

docs/windows-rdna4-port.md

@@ -9,6 +9,23 @@ validation coverage are recorded below. Performance remains in progress.
 
 ## Milestone and gates
 
+Performance diagnostics (2026-10-01): the separate ZLUDA `b0161a4` runtime
+passes 32 PTX launches in each context and all four native K/M frames with
+bit-exact RGB against their controls. All thirteen exported patches (0002
+through 0014) apply to the pinned fresh base. The full Windows build and all
+16 CTest gates pass. Actual K profiling completes 2345 frames with zero backend
+errors. Replacing PowerShell's line-oriented stdout/stderr collection with
+concurrent raw byte copies removes substantial diagnostic backpressure:
+mean Evaluate host time drops from 25.715 to 3.350 ms despite per-kernel HIP
+event synchronization. Native/translated GPU times, scope and limitations are
+in [windows-performance.md](windows-performance.md). Quiet successful API
+logging is separately selectable via `D4R_QUIET_API=1`; error checks stay active.
+
+An additional K game run (`silent-hill2-k-output-stages.zip`) completes 1688
+frames / 18568 native launches / 1688 GPU output scans, all finite, with no
+backend failure or previous-frame output. The user confirms visible imagery
+after the depth-plane fix; low FPS is the current investigation.
+
 Actual K rendering: `silent-hill2-k-depth-plane.zip` completes **1794 DLSS
 frames / 19734 native K launches / zero d4r failures** at 753x424 -> 1280x720
 with the game's depth-inverted HDR path and DXGI-19 depth plane. The captured