GPU selection methods
Flash offers two ways to specify GPU hardware:- GPU pools (
GpuGroup): Select from predefined pools of similar GPUs grouped by architecture and VRAM. - Specific GPU types (
GpuType): Target exact GPU models when you need precise hardware characteristics.
GPU pools
TheGpuGroup enum provides access to GPU pools. Each pool contains specific GPU models grouped by architecture and VRAM capacity.
Available GPU pools
Using GPU pools
Specific GPU types
TheGpuType enum provides access to specific GPU models. Use these when you need exact hardware characteristics.
A single GpuType requests that exact card — this is the only form guaranteed to pin workers to a specific GPU model. If you pass a list of GpuType values, placement is advisory at the pool/VRAM-tier level instead. See GPU selection behavior for details.
Available GPU types
Using specific GPU types
GpuType to its GPU pool (GpuGroup) when it creates the endpoint, excluding any pool members you didn’t list. Placement within the selected pools is advisory: workers may be scheduled on a different card with equivalent VRAM rather than one of the exact models you listed, and list order is not preserved. Pass a single GpuType when your workload requires an exact GPU model.
Advanced fallback strategies
CombineGpuGroup and GpuType for robust availability:
GPU selection behavior
Single GPU type: Passing a singleGpuType requests that exact GPU model. This is the only form guaranteed to pin workers to a specific card. Flash waits for that model to become available, and jobs stay in queue until capacity is free.
GpuGroup requests any card in that pool.
There is currently no API field that reports which GPU model a worker was actually placed on. The endpoint configuration reflects what you requested, not where workers ran, so GPU substitution is invisible in the API. To verify placement, query the GPU from inside the worker (for example, with
nvidia-smi).Multi-GPU workers
Request multiple GPUs per worker usinggpu_count:
Handling unavailability
If requested GPUs are unavailable, jobs stay in queue:-
Add fallback options: Use multiple GPU types.
-
Use broader selection: Switch to
GpuGroup.ANY. - Contact support: For capacity guarantees, contact Runpod support.