# 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 original serializing 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 --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 ` for native wave sizes and compiler spill counts. Reports and proprietary workload inputs remain local. Native FP8 remains a separate optional experiment; the package uses the validated FP16-equivalent baseline. Its later checks and timings are below. ## K host synchronization and asynchronous submission Current priority is K performance. The user's synchronous 4K reading is 49–51 FPS / 53% GPU utilization, versus approximately 80+ FPS / 100% with FSR4. These readings do not identify a CPU hardware limit or provide a controlled same-scene comparison. M/FP8 optimization is deferred. ZLUDA candidate `a1c506f` adds `D4R_ZLUDA_PROFILE_API`, enabled by the game runner's `-ProfileCudaApi`. It measures existing API host durations, aggregates per thread and logs every two seconds without HIP events or additional waits. The synchronous control shows five `cuCtxSynchronize` calls per frame with about 3.9 ms aggregate host time. CUDA launch host overhead is approximately 0.46 ms per frame. Cached copy-list setup is only 0.011 ms median. These host measurements include GPU waits and must not be added to GPU kernel times. | K/4K command submission, CPU median | Synchronous | First async | Async without CUDA mutex | | --- | ---: | ---: | ---: | | Entire submission, ms | 10.512 | 2.676 | 0.181 | | DLSS boundary, ms | 10.083 | 2.604 | 0.124 | | Consumer suffix completion, ms | 0.350 | 0.005 | 0.004 | The first async game run completes 9481 finite frames; the user reports 60 FPS / 63% GPU. The mutex-free run crashes during feature recreation after 366 finite frames, so its submission timing is not a successful gameplay benchmark. The standalone burst/recreate reproducer subsequently identifies caller-owned GPU backing freed after ReleaseFeature returns. Waiting for pending D3D12 consumers in ReleaseFeature fixes the reproducer: all twelve sync/async test frames pass, and corresponding RGB outputs are exact. Game stability and FPS must be checked separately on the fixed build. The fixed game retest on 2026-10-02 completes 16941 K/4K frames, all finite, including feature recreation and color-format reimports, with zero backend failures. The user reports 62 FPS / 63% GPU. Median CPU submission is 0.197 ms, NGX host completion on the worker is 4.400 ms and output validation is 0.380 ms. The 10.162 ms median worker input wait includes queued game rendering. These results establish a stable five-minute test of this fix, not a conclusion about the remaining GPU idle time or FSR4 performance. `-AsyncInterop` is opt-in. It queues input/output fences on the submission thread, executes CUDA on a worker and retires owned command memory by GPU completion. Three copy slots bound outstanding ownership. The queue consumes the output of the same frame, with no CPU image copy. The worker's input wait includes its lead behind submitted rendering and is not a CPU submission stall. Neither that duration nor the NGX recording interval measures Present latency. Reconfiguration waits for all consumers; ordinary submission does not hold the CUDA mutex. The experimental runtime currently supports one queue. ```powershell .\scripts\windows\test-async-k.ps1 ``` The test generates fresh synchronous controls, submits three frames without intermediate CPU completion, and repeats while releasing/recreating the DLSS feature with work pending. Results include exact RGB comparisons, finite GPU scans, stdout/stderr, exceptions and runtime provenance. To include the local validated output-store optimization, pass its combined native directory with `-NativeRoot`; proprietary objects remain local. `-ProfileGpuBoundary` (requires `-AsyncInterop`) adds D3D12 timestamps before and after the VRAM input/output copies. Resolved results are read only once the copy slot's existing fence completes; 32 diagnostic bytes per frame are read and no new completion wait is added. `external_span_ms` spans HIP and host/driver scheduling across the external fence. `between_boundaries_ms` also includes game rendering, and `input_interval_ms` is not Present timing. These queries obey the queue's timestamp ordering and add GPU commands; they are disabled for an ordinary FPS run. GPU clock behavior during idle can affect intervals; no hardware occupancy is inferred. Timestamp semantics: [Microsoft D3D12 timing](https://learn.microsoft.com/en-us/windows/win32/direct3d12/timing). The timestamp-enabled 4K burst/recreation gate completes twelve frames, all finite; all six async RGB outputs still match their fresh controls exactly. Each async mode emits all three timing records, including the final frame at feature release. Results: `test-results/k-async-gpu-boundary-4k`. All sixteen CTest gates pass on the rebuilt shim. Reproduce with: ```powershell .\scripts\windows\test-async-k.ps1 -ProfileGpuBoundary ``` The 2026-10-02 game timestamp run completes 9384 K/4K frames without backend errors (`test-results/silent-hill2-k-gpu-boundary-4k`). Median GPU intervals: input copies 0.061 ms, external span 5.586 ms, output copy 0.208 ms, entire boundary 5.856 ms, between boundaries 9.512 ms. Median input interval is 15.383 ms. Output scans and serializing kernel events are off. This locates the remaining time outside the small D3D12 copies; it does not prove whether that time is game GPU work, CPU waits or context scheduling. ### Present and GPU-busy capture `capture-presentmon.ps1` attaches the official PresentMon 2.6.0 x64 CLI to one running game process. It verifies SHA256 `b2a706bc6ad475749e3b7e3409263aa1e6906d45bdcf993f6dbc0f660188f1af`, uses a unique ETW session and stops at its time bound/process exit, without replacing any existing trace or installing a service. It saves CSV, console output, driver version, target PID and the HWS registry setting. The default downloads the pinned CLI into `.tools` if needed. Run elevated when ETW access requires it; no driver or security setting is changed. ```powershell .\scripts\windows\capture-presentmon.ps1 -Seconds 30 python .\tools\windows\profile_report.py --output profile.json ``` Keep the game foreground and use the same scene/quality setting for comparison. The report separates swapchains and preserves missing metrics. Present FPS comes from present intervals, rather than NGX recording timestamps. GPU busy/wait are ETW estimates, not a hardware sensor percentage; CPU busy is frame work/wait attribution before Present, not physical CPU utilization. HWS and cross-API context attribution can affect accuracy. Metric definitions: [PresentMon console documentation](https://github.com/GameTechDev/PresentMon/blob/v2.6.0/README-ConsoleApplication.md). The initial 60-second trace captures 2172 presents during a changing Independent Flip / Composed Flip session, with mean present interval 27.593 ms (36.241 FPS), mean GPU busy 18.759 ms and GPU wait 2.303 ms. This is not a controlled capture of the user's 62 FPS scene and is excluded from speedup conclusions. Its containing game run completes 9627 K/4K frames without backend errors; ordinary recording intervals later return to about 16 ms. A stable foreground-scene capture is needed before optimizing from the ETW metrics. Raw files: `test-results/silent-hill2-k-presentmon-4k`. The following 30-second capture starts after the user confirms the same foreground scene is ready. All 1902 presents use Hardware Independent Flip and SyncInterval 0; input/output resolution remains 2259x1271 -> 3840x2160. The mean present interval is 15.730 ms (**63.574 FPS**). PresentMon estimates mean GPU busy/wait at 14.504/1.110 ms, GPU time at 15.614 ms and CPU wait at 0.052 ms. These frame-attributed metrics do not equal a hardware utilization sensor and do not establish a physical CPU limit. FSR4 has not been captured in this same scene, so its previously reported 80+ FPS remains a user reading. Raw files: `test-results/silent-hill2-k-steady-profile-4k`. The containing ten-minute diagnostic completes 36591 K frames, with zero backend failures, CPU image copies, previous-frame outputs or recorded game crashes. It deliberately stops at its time bound. Output scans and serializing kernel events are off. Whole-run median boundary timestamps measure input copies 0.063 ms, external span 5.399 ms and output copies 0.212 ms. The external span includes HIP execution and host/driver scheduling, not only transformer arithmetic. These medians cover the whole run; the PresentMon numbers above come from the explicitly selected 30-second scene. ### Deferred kernel events and batched inputs The new optional `-ProfileKernelsDeferred` samples every seventeenth launch by default (`-KernelProfileEvery`). Its thread-local pool is bounded to 64 event pairs. It queries ready events before selected launches and after the application's existing context synchronization, reusing a pair only after reading its old timestamps. It adds no explicit event/stream/device completion wait; timestamps, queries and logging still add overhead. Stream capture and legacy default-stream launches are skipped by default. `-ProfileLegacyStream` allows the latter explicitly, retaining their legacy cross-stream ordering. This opt-in is necessary to profile this DLSS K binary, whose measured launches use the legacy default stream. `completion_ms` now denotes collection lag for deferred records. The report separates serializing/deferred records and retains invalid timestamps and skipped samples outside kernel timing statistics. HIP 7.17.26386 reports some negative elapsed times in the tiny queued PTX diagnostic, including intervals exceeding one microsecond. These are logged as `D4R_KERNEL_PROFILE_INVALID`; they are not clamped or used as valid GPU samples. The cause is not established, and nonnegative samples alone cannot prove a runtime's timestamp accuracy. The diagnostic verifies all 516 PTX launches across primary/created contexts and individual/queued submission, checks final device output and guards, accounts for every collected event and verifies safe default-stream skipping. Results: `test-results/zluda-deferred-profile-final-ptx`. The same diagnostic with stable HIP SDK 7.2 also verifies all 516 outputs and reproduces negative intervals (`test-results/zluda-deferred-profile-stable-ptx`). A native K dec4 sample is negative too; this is not confined to tiny PTX kernels. Do not infer hardware/kernel utilization or a speedup from these event samples. HIP event semantics: [AMD event management](https://rocm.docs.amd.com/projects/HIP/en/latest/reference/hip_runtime_api/modules/event_management.html). The opt-in `-BatchInputCopies` (`D4R_BATCH_INPUT_COPIES=1`) enqueues native pixel decoding and device-to-array input copies on the shared HIP/ZLUDA legacy default stream. One all-stream completion remains before NGX can use any input on its own streams. The independent D3D12 input-fence check, NGX completion and same-frame output dependency remain. Output transfers retain their existing completion. Every image stays in VRAM. The ZLUDA implementation adds `cuMemcpy2DAsync_v2` using `hipMemcpyParam2DAsync`; format-80 array emulation is explicitly rejected because its synchronous implementation uses temporary host storage. The Windows path supplies canonical FP16/FP32 arrays instead. This experiment remains disabled by default. Correctness checks pass, but the controlled game comparison below shows only a small frame-time difference. ```powershell .\scripts\windows\test-deferred-kernel-profile.ps1 .\scripts\windows\test-async-k.ps1 -BatchInputCopies -ProfileGpuBoundary -ZludaRoot "$PWD\dist\zluda-windows-deferred-profile" ``` The rebuilt Windows shim and new ZLUDA pass all seventeen CTest gates, including the added asynchronous pitched FP16/FP32 array-copy test and padding checks. Completed boundary timestamps are also read before reuse if the copy fence advances between the first completion scan and slot selection; this prevents diagnostic records being overwritten without adding a wait. The depth/stencil and packed-format burst/recreation gates pass 24 full K/4K frames. All twelve candidate RGB outputs match fresh unbatched synchronous controls exactly, with finite RGBA. The former also enables deferred legacy events; invalid timestamps remain separate. These short correctness fixtures include initialization and do not establish steady-state FPS or a copy-stage speedup. Raw results: `test-results/k-batch-deferred-4k` and `test-results/k-batch-packed-4k`. ZLUDA candidate source is `67127dd`, isolated in `dist/zluda-windows-deferred-profile`; patches 0016/0017 and all preceding patches apply to the clean pinned base. The public prerelease is unchanged. After committing/rebuilding ZLUDA with a clean worktree, the twelve-frame four-way K/4K gate passes again with exact candidate RGB and finite RGBA (`test-results/k-batch-committed-source-4k`). This warms the committed runtime's JIT cache before the game comparison. The following user-confirmed 30-second foreground-scene capture contains 1925 presents at **64.265 FPS**, versus the previous unbatched run's 63.574 FPS. Both use 2259x1271 -> 3840x2160, Independent Flip and SyncInterval 0, without kernel-event profiling, output scans or attached debuggers. Mean present time is 15.561 versus 15.730 ms, a 0.169 ms difference. This single pair does not establish repeatability or a large performance improvement. The containing ten-minute candidate run completes 35673 K frames with zero backend failures, CPU image copies, previous-frame outputs or recorded game crashes. Whole-run median input preparation drops from 0.482 to 0.332 ms; median external span is 5.438 versus 5.399 ms. Whole-run stages are not the selected PresentMon window. No GPU utilization conclusion is drawn from ETW estimates. Results: `test-results/silent-hill2-k-batch-inputs-4k`. The K performance gate stays open. ### AMD driver telemetry A separate read-only diagnostic polls the installed driver's ADLX base C interfaces for device-wide usage, core/VRAM clocks, board power and temperatures. It adds no work to game queues and changes no tuning setting. Build it locally using the official SDK pinned at `32b5a740d42295c5dfe9026b9f52683da0f3af91`: ```powershell .\scripts\windows\build-gpu-telemetry.ps1 .\scripts\windows\capture-presentmon.ps1 -Seconds 30 -GpuTelemetry ``` The SDK retains its own AMD license; SDK headers, implementations, driver DLLs and the SDK-dependent executable are excluded from public game packages. The probe is independently written and uses the documented C ABI, including with LLVM-MinGW. It loads `amdadlx64.dll` only from Windows System32 and releases acquired interfaces before ADLX termination/unload. GPU selection must match exactly one device (`-GpuName` selects a different name substring). The process exits at its bound or target process exit. The capture retains CSV, raw stderr, exit/timeout, driver DLL version/hash and SDK build identity. No optional telemetry failure is silently converted to a valid measurement. CSV records independent host UTC/QPC timestamps and the driver's raw sample timestamp. On this installed ADLX 1.5.0.124, the latter is uptime despite the SDK description of epoch time; do not interpret it as UTC. Unsupported metrics are blank, zero utilization/clock remains valid, and the report uses each driver timestamp once. Device-wide usage is distinct from PresentMon's per-process frame attribution and is not measured WMMA occupancy. ADLX API: [AMD GPU metrics sample](https://gpuopen.com/manuals/adlx/adlx-c__perf_g_p_u_metrics/). The initial idle-device smoke test captures six valid polls, selects the real RX 9070 XT and terminates ADLX successfully. Board power/core clock/usage and temperatures are available; `GPUPower` is unsupported and stays absent from the report. The first poll costs roughly 10 ms for initialization; subsequent polls are about 0.08 ms at 500 ms intervals. This idle smoke test does not establish game clocks, utilization or an overhead-free benchmark. Results: `test-results/gpu-telemetry-smoke`. The subsequent combined-capture smoke test collects 246 presents and ten ADLX polls and exits cleanly (`test-results/gpu-telemetry-capture-smoke`). It includes startup/scene changes and is excluded from FPS comparisons. After the user confirms the foreground comparison scene, the 30-second run with detailed d4r stages/boundary timestamps disabled records **64.661 FPS** over 1935 presents. ADLX's sixty polls report mean usage **93.183%**, core clock **3124.667 MHz**, board power **316.717 W**, temperature 57 C and hotspot 82.9 C. Mean PresentMon GPU busy/wait is 14.551/0.800 ms. All presents retain Independent Flip / SyncInterval 0. This records high device-wide driver usage in this run; the previous user-reported 63% has not been captured from the same sensor/window and its discrepancy is unresolved. Do not infer a physical CPU limit, isolated shader occupancy or a FSR4 speed comparison. Query overhead is median 0.094 ms per 500 ms poll, with a roughly 12 ms first query. Results: `test-results/silent-hill2-k-telemetry-unprofiled-4k`. The game stability summary is still pending its existing ten-minute bound. Remaining K work now prioritizes transformer/output-kernel cost; frame scheduling remains measured. Further game coverage (HIP kernel profiling disabled, GPU output checks enabled): M at 1920x1080 completes 4833 frames, all finite. K at 3840x2160 completes 4685 frames, all finite. Neither has a backend failure, CPU image copy or an aged-frame fallback. Their mean interop/NGX CPU stages total about 13.6 and 10.1 ms respectively; these are different scenes, not a K/M comparison. The no-debugger K/4K run completes 5774 frames, with 5774 finite output scans and 63514 native transformer launches. The user reports 38-42 FPS. Additional CPU measurements exclude replay/publication as the main cause of low FPS: | CPU measurement | Mean, ms | Median, ms | | --- | ---: | ---: | | Command split setup | 0.284 | 0.275 | | State replay within split setup | 0.025 | 0.023 | | Submitted texture state publication | 0.029 | 0.029 | | Consumer suffix completion | 0.405 | 0.409 | | NGX recording interval | 27.474 | 28.466 | Recording intervals are between NGX recording calls on the same thread, not DXGI Present times. The interval includes rendering and application scheduling. A second K/4K run with the attached debugger completes 3567 frames without failure, with median recording interval 30.091 ms. The runs include different menu/game states; this does not establish a precise debugger FPS speedup. Its sparse debugger events also rule out a per-kernel OutputDebugString storm. An earlier control that stayed on the startup screen completed zero DLSS frames and is excluded. Normal game launches now omit the attached debugger; crash diagnostics remain available with `-CaptureExceptions`. The 2961-frame 4K K profile identifies the translated output tail as its largest kernel: 4.401670 ms mean GPU time, versus about 2.875 ms for all eleven native transformer layers combined. Ported upstream's texture-store recipe to native Windows. It retains accuracy mode, wave32, FP16 subnormals and f16 reference accumulation; native FP8 remains disabled. Both output variants execute on every checked frame and match the previous RGB output bit-exactly: eight consecutive 512x288 frames per variant, then three consecutive 3840x2160 frames per variant. All RGBA components are finite. Identical synthetic inputs and public NGX flags give these 4K event times (three samples each; host initialization and readback are outside the event): | K output variant | Translated mean, ms | Native stores mean, ms | | --- | ---: | ---: | | LDR, regular depth, high-resolution MV | 2.907823 | 1.803233 | | HDR, inverted depth, low-resolution MV | 2.978547 | 2.088347 | A subsequent game run executes 6221 frames with the native HDR output tail, zero backend failures and mean tail GPU time 1.801918 ms. The earlier game profile's 4.401670 ms is from a different scene/scheduling state; use the identical-input table for the controlled comparison, not an inferred FPS multiplier. This profiled game run did not enable the NaN scan. Reproduce the private texture build and full-frame comparisons: ```powershell .\scripts\windows\build-native-texture.ps1 -DlssDll "$PWD\nvngx_dlss.dll" .\scripts\windows\build-native-texture.ps1 -DlssDll "$PWD\nvngx_dlss.dll" -Kernel hiluma_engine_output_depthreg_mvhi_ldr_max_v2_rel .\scripts\windows\test-native-texture.ps1 -OutputResolution 3840x2160 -Iterations 3 ``` These objects contain code derived from the locally supplied NVIDIA PTX. They stay in ignored local directories and are excluded from the public package. The installer accepts them with `-LocalTextureKernels` only after validation, checking the exact DLL identity, object and manifest hashes. M retains its independently validated FP16-equivalent baseline. The following no-debugger K/4K run completes 9982 frames and 9982 finite GPU scans. Kernel event profiling is disabled; the validated private output tail executes natively. The user reports 43-47 FPS. Mean NGX recording interval is 21.867 ms. No backend failure, CPU image copy or previous-frame output occurs. Random one-in-64 hook samples then identify contention in the shared routing table used by every intercepted D3D12 command. Per-thread weak lookup caches now bypass that table on repeated calls to a list. Table mutations invalidate cache generations; Reset/address reuse cannot route to a previous suffix, and thread caches do not retain game resources. The per-list and submission locks remain. A GPU regression resets and re-splits the exact same list with changed root constants twice per iteration, checking both prefix and suffix results. | Sampled command-hook access | Shared table | Per-thread weak cache | | --- | ---: | ---: | | Busiest recording thread, mean us/call | 0.203 | 0.066 | | Estimated access + capture across threads, ms/s | 977.528 | 233.606 | The latter estimate includes lock waits summed across concurrently running threads, not CPU execution time or serial frame latency. The two game runs have different thread populations (31 versus 29); there is no identical frame trace. Generated forwarding methods have separate driver/capture markers; special-case hooks contribute access samples but lack those body markers. With the cache, 4770 complete K/4K frames and finite GPU scans pass, with zero backend failures, CPU image copies or previous-frame output. Median NGX recording interval is 19.473 ms. The user reports 49-51 FPS and 53% GPU usage in the previously measured scene. These user readings are separate from the sampled hook estimates and do not establish isolated WMMA utilization. All sixteen CTest gates pass, including 64 same-object Reset/split checks in each physical command-backend test and the software indirect-root regression. Use `-ProfileCommandHooks -ProfileStages` to collect samples; the sampler is disabled for ordinary play. Native M FP8 was subsequently compiled and tested on this gfx1201. ISA confirms `v_wmma_f32_16x16x16_fp8_fp8`, with packed e4m3 weight images; exact FP16 attention/PV remains. All logical outputs and merges in forty recorded launches match the previously NumPy-validated FP16 baseline byte-for-byte. Full DLSS RGB also matches exactly: four 512x288 LDR frames and four 3840x2160 HDR frames, all RGBA finite. This establishes correctness for those fixtures, not a speedup. The original software operand packing makes the FP8 network slower in the four-frame 4K test: sum of five main-kernel event means (tube weighted six times) is 27.789640 ms versus FP16's 23.550875 ms. A paired in-process replay confirms the regression without relying solely on separate process timings. Both modules and prepared weights remain resident, 512 launches warm the GPU, then sixty-four AB/BA pairs time the same restored input using HIP events. Diagnostic CPU input restoration is outside the timed event and is unrelated to game VRAM interop. Added opt-in `D4R_FP8_HW_PACK`: native packed conversion of already quantised operands replaces software exponent/subnormal reconstruction. It preserves all 254 finite OCP e4m3 encodings, including signed zero, in an exhaustive GPU check. All forty recorded launches still match exactly. Four complete 4K HDR frames also match FP16 RGB exactly with finite RGBA. ISA confirms both packed converts and FP8 WMMA. The baseline build's sixteen objects remain byte-identical. | Paired replay median, ms | FP16 (software-packing test) | FP8 software packing | FP16 (hardware-packing test) | FP8 hardware packing | | --- | ---: | ---: | ---: | ---: | | enc1 | 0.175450 | 0.217050 | 0.175100 | 0.177700 | | enc2 | 0.141350 | 0.164550 | 0.132550 | 0.131550 | | enc3 tube | 0.108000 | 0.112000 | 0.107600 | 0.099850 | | dec2 | 0.129900 | 0.146000 | 0.143250 | 0.140850 | | dec1 | 0.169650 | 0.194450 | 0.154250 | 0.156550 | These are two paired tests on the captured 512x288 workload. Medians avoid large isolated scheduling outliers; raw per-pair ratios are retained. They identify a substantial cost in software packing but do not establish an overall FPS gain. The separately run four-frame 4K hardware-packing network mean is 24.603463 ms; it still does not beat the measured FP16 total. Default packaging retains FP16. Hardware counters for bandwidth or WMMA utilization were not measured. Reproduce the isolated build, encoding/replay checks and paired timings using the existing private validated captures; no source editing is required: ```powershell .\scripts\windows\build-native-m-fp8.ps1 -DlssDll "$PWD\nvngx_dlss.dll" -HardwarePacking .\scripts\windows\test-native-m-fp8.ps1 -ModuleDirectory "$PWD\build\native-m-fp8-hardware-pack" -CaptureDirectory "$PWD\test-results\ngx-m-exact-pv-capture\captures" -BaselineValidation "$PWD\test-results\m-native-exact-pv-temporal-reference\summary.json" -Benchmark ``` Omit `-HardwarePacking` to compile the original FP8 experiment. The replay validator stops at the first mismatch, retains GPU stdout/stderr/exit code and hashes every compared logical output. `profile_report.py` accepts replay logs and reports per-pair GPU time and candidate/control ratios. This experiment is not installed by the game runner or substituted silently for the baseline. The conversion builtin is listed in the official [Clang AMDGPU builtin reference](https://clang.llvm.org/docs/AMDGPUBuiltinReference.html#builtin-amdgcn-cvt-pk-fp8-f32). 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).