FluidRuntime

A Windows research runtime for finding and safely removing redundant work between CPU, GPU, RAM, VRAM, and the graphics pipeline.

FluidRuntime is the actuation companion to FluidGateway. Gateway diagnoses probable waste and makes bounded decisions; Runtime proves whether an action can be applied without changing the result.

Current Status

Area	State
FluidLink v2	Strict binary IPC with numeric opcodes and no JSON payloads
FluidLink batch	129 logical operations in one ordered request/vector pair
D3D11	Reversible copy, readback, staging upload, and direct upload labs
D3D12	Gateway-authorized multi-lane buffer elision with queue/fence provenance
Native telemetry	Persistent read-only process, RAM, VRAM, and GPU-engine series
Vulkan	Planned, not implemented
External games	Unsupported; owned opt-in workloads only

Persistent Native Telemetry

fluidruntime inspect can collect up to 100 native GPU/VRAM snapshots without launching a probe process per sample. The native probe keeps one bounded PDH session alive, reuses its counters, and emits an ordered native_probe_samples series. The default remains one snapshot.

fluidruntime inspect --ledger ledger.json --out report.json --pid 1234 `
  --samples 30 --interval-ms 1000 `
  --native-probe fluidruntime-native-probe.exe --native-probe-samples 30

This path is observational and read-only. It does not inject, hook, schedule, change residency, or optimize the target process.

v0.21.2 CI Portability Hotfix

This hotfix derives the Microsoft AddressSanitizer runtime location from the toolchain selected by CMake. It supports current GitHub runners whether Visual Studio is installed under Program Files or Program Files (x86) and leaves the v0.21.1 runtime authority and wire contracts unchanged.

v0.21.1 Safety Release

This patch does not widen native authority. It makes the current owned-lab path safer to run locally: every launched target is terminated and reaped on timeout or cancellation, native-probe duration is bounded, evidence files are replaced atomically, and the native toolchain treats warnings as errors with SDL and Control Flow Guard enabled. MSVC code analysis is clean for the two targets that previously reported null-dereference and excessive-stack warnings.

v0.21 Result

The D3D12 path now consumes a backend-neutral transfer contract covering queues, execution scopes, resources, lanes, operations, and fences. Across 30 measured RX 580 pairs plus one warmup:

• two command lists and two independent destination lanes preserved exact final content while each optimized run omitted 128 redundant 4 MiB calls;
• baseline forwarded 136 tracked calls; optimized forwarded the eight required guards and skipped 128 candidates;
• submit-to-fence delta p50/p95/p99 was -45.817 / -42.616 / -37.080 ms, with 30/30 optimized wins;
• GPU timestamp delta p50/p95/p99 was -46.870 / -42.814 / -38.004 ms, also with 30/30 wins;
• the native execution gate passed, but the complete managed path did not: end-to-end p95/p99 was +18.262 / +53.557 ms, so the product-level performance claim remains blocked;
• malformed, stalled, and slow peers published no policy and completed an all-forwarded 136-call baseline with zero skips.

The reusable contract, transfer event/action opcodes, unique destination ownership rule, and numeric backend/operation IDs are ready for a Vulkan implementation. Vulkan itself is not implemented in this release.

This is measured protocol and functional evidence. It is not yet a claim of lower game latency, higher FPS, reduced PCIe traffic, lower power, or physical RAM/VRAM savings.

How It Fits

PresentMon + Windows telemetry
             |
        FluidGateway
      diagnosis + policy
             |
       FluidLink binary IPC
             |
        FluidRuntime
 proof + bounded owned action
             |
   native D3D11/D3D12 labs

Verify Locally

Requirements: Windows, Python 3.11+, .NET 10 SDK, CMake, and an x64 C++ toolchain for native labs.

dotnet test FluidRuntime.slnx -c Debug
dotnet build FluidRuntime.slnx -c Release -warnaserror

powershell -NoProfile -ExecutionPolicy Bypass `
  -File tools/Test-FluidLinkIntegration.ps1 `
  -GatewayPath ..\FluidGateway

powershell -NoProfile -ExecutionPolicy Bypass `
  -File tools/Test-GatewayManagedD3D12Copy.ps1 `
  -GatewayPath ..\FluidGateway `
  -CandidateActionCount 128 `
  -TrialPairs 2 -WarmupPairs 0 -Hardware $false

Safety Boundary

FluidRuntime does not currently inject into third-party games, alter drivers, schedule Windows threads, control physical residency, or promise unified-memory behavior in software. Native intervention is limited to owned deterministic targets, short-lived policies, exact equivalence checks, bounded action budgets, and verified rollback.

FluidRuntime launches and terminates only executables supplied to explicit lab commands. It does not discover arbitrary games or inject into an external PID.

Documentation

• Current status and release gate
• Architecture and trust boundaries
• Roadmap
• v0.21 generalized D3D12 transfer evidence
• v0.21.1 local-use hardening evidence
• v0.21.2 CI portability evidence
• v0.20 single-lane D3D12 evidence
• v0.19 end-to-end authorization evidence
• v0.18 resilience and 128-action evidence
• FluidLink v0.17 batch evidence
• D3D12 observation evidence
• Project handoff briefing

FluidRuntime is open source under the MIT License.