# Build and verification record

## Objective

Create a reproducible DS4 package that maximizes target-model quality within a
128 GB unified-memory envelope. Preserve exact native MXFP4 routed experts on
the ten sensitivity-selected layers and retain the proven low-bit/Q8 policy
everywhere else.

## Inputs and toolchain

- All weights were regenerated from
  `apetersson/DeepSeek-V4-Flash-0731-Abliterated-FP8`.
- The sparse reference GGUF supplied metadata, tokenizer, tensor order and
  shapes only.
- All 48 source-shard hashes, source metadata and the abliteration manifest
  were verified before conversion.
- The routed-expert imatrix supplied exact coverage for the 129 tensors whose
  output types consume calibration data.
- DS4 source revision: `d516d4eeb82c454aeb2831af1b1961801d6b571b`.
- Upstream `ds4f-mxfp4` base: `4893e0c40fba03dbc85555faeb035799aa04e0b6`.
- Quantizer SHA-256: `f0a381f4ada808ea2afa740d964354fa327fc1235ba7cebf50874eb89fb97ac5`.
- Runtime SHA-256: `2aaf20469b9918d6d6ab8787a02811c11228547cd979787879a03dba8a9e7824`.

## Quantization policy

- Native MXFP4 gate/up/down routed experts on layers
  `10, 14, 30, 34, 37, 38, 39, 40, 41, 42`.
- IQ2_XXS gate/up and Q2_K down routed experts on the other 33 MoE layers.
- Q8 attention, shared-expert and output tensors.
- Protected F16 indexer and auxiliary tensors.
- DSpark support with IQ2_XXS gate/up and native MXFP4 down projections for
  target layers 40, 41 and 42.

## Conversion gates

- Strict imatrix mode passed for main and DSpark conversions.
- Main GGUF contains exactly 1,328 tensors and the intended 30 MXFP4 tensors.
- DSpark support contains exactly 81 tensors and three MXFP4 down aggregates.
- Every native tensor comparison required an explicit `byte_compare: OK`.
- All 30 main and three DSpark MXFP4 tensors independently reproduced the
  source FP4 codes and scale bytes.
- `ds4 --cpu --inspect --dspark-strict` reported zero missing tensors, invalid
  bindings or metadata errors.
- The final GGUF hashes are recorded in `SHA256SUMS`.

## Result

| Component | Bytes | GiB |
| --- | ---: | ---: |
| Main GGUF | `102,826,238,912` | `95.7644` |
| DSpark support | `7,297,737,120` | `6.7965` |
| Combined | `110,123,976,032` | `102.5609` |

Native MXFP4 improves fidelity over a second Q4_K requantization and uses 4.25
bits per weight rather than 4.50. Native MXFP4 Metal and the mixed DSpark path
are newer than mature Q4_K kernels, so throughput should be measured on the
target system.

## One-million-token context

Recommended target-only mode:

```sh
ds4 --metal \
  -m DeepSeek-V4-Flash-0731-Abliterated-DS4-Quality128.gguf \
  --ctx 1048576 --prefill-chunk 2048
```

Estimated residency is at most `110.30 GiB`. DSpark can be tested with a 1,024
token prefill chunk; estimated residency is `114.02 GiB`. A 4,096-token chunk
with DSpark is estimated at `123.24 GiB` and is not a reliably resident mode on
a machine whose Metal recommended working set is approximately `121.60 GiB`.