In this article
Single-slot fit and a verified16GB workload are independent acceptance conditions.
NVIDIA RTX A4000 is assessed here as an exact Ampere board configuration. Its published 16 GB capacity is the starting point for a workload qualification, not a measured serving or rendering result.
Exact model and memory variants
RTX A4000 provides16 GB GDDR6 ECC in a 140 W active full-height single-slot card. It is distinct from 20 GB Ada 4000 and 24 GB Blackwell 4000.
| Variant | Memory | Published board power | Cooling / format |
|---|---|---|---|
| NVIDIA RTX A4000 | 16 GB GDDR6 ECC | 140 W | Active; full-height single slot |
Specifications: Official product/support documentation.
LLM backend and memory budget
Evaluate the 16 GB Ampere budget with the full runtime and weights. A successful small control model does not automatically authorize increasing context or concurrent requests.
Passing the architecture requirement does not certify every model, quantization kernel or prebuilt package.
Compatibility evidence: vLLM GPU requirements.
Cycles and batch rendering
Second-generation RT cores apply to supported rendering paths. On the single-slot card, measure complete scene execution in the final environment, including denoising and desktop-memory reservation.
Blender 5.2 LTS GPU rendering manual.
Integration into a server or workstation
A single slot is a mechanical advantage, not a server thermal certification. The full-height9.5-inch board still requires intake clearance. Preserve nearby expansion-card positions and the closed-chassis state in every sustained qualification.
A concrete qualification scenario
A lab adds A4000 to a host that also contains storage and network adapters. Save an installation photo and slot map. Execute a bounded16 GB inference case with the normal services present, then render a complete reference frame. Repeat after any change in adapter placement rather than attributing altered behavior immediately to the model. Keep the installation evidence beside the artifact hashes.
The evidence to retain
Keep an ordinary qualification record with the actual test outputs.
Identify the tested variant, software build and execution mode before entering observations. Leave unavailable measurements explicitly unknown.
The fields below separate published specifications from observed allocation and job completion, so a later operator can repeat the same case.
| Evidence field | What this profile must retain |
|---|---|
| Hardware identity | NVIDIA RTX A4000; physical variant and reported device identifier |
| Memory boundary | 16 GB published; observed free memory before and after loading |
| Inference artifact | Exact weights digest, quantization, context and offload configuration |
| Render artifact | Scene digest, renderer version, backend and denoising setting |
| System envelope | Driver, container/build digest, enclosure and cooling configuration |
| Completion evidence | Application exit status, output validity and observed memory failures |
Moving another adapter beside A4000 changes the tested installation even when weights, driver and 16 GB capacity remain unchanged.
Further reading: VRAM for LLMs: why model size is only part of the calculation, Idle render farms: assessing a second GPU workload, NVIDIA and AMD GPU catalogue.