Source: https://guthlabs.ai/docs/instruments/gpu-vram-vs-model-size-ladder/implementation/

instrument implementation / implementation-contract

# GPU VRAM vs Model Size Ladder implementation

A source-bound implementation contract for GPU VRAM vs Model Size Ladder; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t4-052

**Effect**: Computation or source lookup only

## Input and validation requirements

An extreme but numerically representable parameter_count causes the JavaScript arithmetic to overflow to Infinity, so the instrument must reject or explicitly flag non-finite estimates. The specification also leaves int4 packing, metadata overhead, and GB-versus-GiB display conventions ambiguous.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "parameters": 7000000000,
    "precision": "fp16",
    "bytes_per_param": 2,
    "overhead_factor": 1.2,
    "context_length": 4096,
    "batch_size": 1,
    "layers": 32,
    "kv_heads": 32,
    "head_dimension": 128,
    "kv_dtype": "fp16",
    "kv_bytes_per_element": 2
  },
  "expected_outputs": {
    "weight_bytes": 16800000000,
    "kv_cache_bytes": 2147483648,
    "total_vram_bytes": 18947483648,
    "total_vram_gib": 17.646
  },
  "working": "Weights = 7000000000 × 2 × 1.2 = 16800000000 bytes. KV cache = 2 × 1 × 4096 × 32 × 32 × 128 × 2 = 2147483648 bytes. Total = 16800000000 + 2147483648 = 18947483648 bytes. GiB = 18947483648 ÷ 1073741824 = 17.646 GiB."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/gpu-vram-vs-model-size-ladder/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/gpu-vram-vs-model-size-ladder/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/gpu-vram-vs-model-size-ladder/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche4/tranche4-results.json`