MultiGpuHelper 1.1.0

MultiGpuHelper

MultiGpuHelper is a .NET Standard 2.0 library for discovering GPU adapters, selecting a device, and limiting concurrent GPU work. Discovery is best-effort: each backend reports only data available from its underlying operating-system, command-line, or driver API.

What it does

• Discovers devices through nvidia-smi, the CUDA Driver API, ROCm rocminfo, or Windows WMI.
• Represents discovery results as immutable GpuDeviceInfo snapshots.
• Selects devices using first-available, most-free-memory, round-robin, or specific-device policies.
• Dispatches callbacks with per-device concurrency limits and soft VRAM reservations.

What it does not do

The library does not execute CUDA, ROCm, DirectX, or machine-learning kernels. It does not allocate physical VRAM, guarantee that reported free memory remains current, or merge records from different discovery backends.

Supported platforms and backends

ROCm behavior has unit coverage but has not been maintainer-verified on AMD hardware. See backend details.

Installation

dotnet add package MultiGpuHelper --version 1.1.0

Quick start

using MultiGpuHelper.Backends;
using MultiGpuHelper.Models;
using MultiGpuHelper.Selection;

var backend = new NvidiaBackend();
var devices = await backend.DetectDevicesAsync();
var selection = new GpuSelectionEngine().SelectDevice(
    devices,
    GpuPolicy.MostFreeMemory);

if (selection.IsSuccess)
    Console.WriteLine($"Selected {selection.SelectedDevice.DeviceName}");
else
    Console.WriteLine(selection.Reason);

Device discovery

Backends implement IGpuBackend. An empty result means the backend was unavailable, failed, or detected no devices; use IsAvailableAsync when that distinction matters. GpuDeviceInfo.Backend identifies the discovery mechanism and Vendor identifies the hardware vendor.

Device selection

GpuSelectionEngine accepts immutable discovery snapshots. FirstAvailable, MostFreeMemory, RoundRobin, and SpecificDevice have unique values and behavior. Unknown memory is represented by GpuMemoryInfo.State, not by treating zero as measured free VRAM.

Dispatching work

GpuDispatcher operates on mutable GpuDevice scheduling registrations managed by GpuManager. Its cancellation-aware overload accepts Func<int, CancellationToken, Task<T>>. GpuWorkItem.TimeoutMs covers waiting and callback execution, but callback cancellation is cooperative.

Error handling

Selection failures from GpuManager throw GpuSelectionException; budget rejection throws GpuBudgetExceededException; caller cancellation and timeouts surface as OperationCanceledException. Callback exceptions propagate unchanged. See error handling.

Thread safety

Concurrent manager selection and dispatcher calls are synchronized. Objects returned by GpuManager.Devices remain mutable; do not change device configuration while work is being dispatched. See threading semantics.

Limitations

• Device IDs are backend-local ordinals, not persistent physical identifiers.
• Results from multiple backends are not deduplicated.
• WMI VRAM is unknown because AdapterRAM is not authoritative for modern adapters.
• Soft VRAM reservations do not allocate or measure hardware memory.
• Hardware-dependent discovery varies with installed tools, drivers, and permissions.

Documentation

• Quick start
• Cookbook
• Backends
• Error handling
• Threading
• Troubleshooting

Contributing / Issues

Bug reports should include MultiGpuHelper version, OS, .NET version, GPU model, driver/runtime version, backend, a minimal reproduction, and the exception with stack trace. Use the GitHub issue tracker.

License

MIT. See LICENSE.