### 🔀 [#146](https://github.com/ikawrakow/ik_llama.cpp/pull/146) - IQ2_K_R4

| **Author** | `ikawrakow` |
| :--- | :--- |
| **State** | ❌ **Closed** |
| **Created** | 2024-12-17 |
| **Updated** | 2024-12-17 |

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#### Description

Adding `IQ2_K` with 4 interleaved rows.

We get very signifiant performance gains on `ARM_NEON` and more modest gains on `AVX2/Zen4`. 

Here is `PP-512` for LLaMA-3.1-8B on `Zen4` (Ryzen-7950X), `ARM_NEON` (M2-Max) and `AVX2` (Ryzen-5975WX)

| Platform |  Threads | IQ2_K | IQ2_K_R4 | Speedup |
| ---: | ---: | ---: | ---: | ---: |
| ARM_NEON |  8 |  59.71 ± 0.91  | 107.93 ± 0.75 | 1.808 |
| Zen4            | 16 | 198.79 ± 0.58 | 250.19 ± 0.42   | 1.259 |
| AVX2           | 32 | 209.02 ± 0.16 |  287.17 ± 0.64  | 1.374 |

We get decent performance gains for TG as well.
Here results for TG-128 on LLaMA-3.1-8B with different numbers of threads:

| Platform |  Threads | IQ2_K | IQ2_K_R4 | Speedup |
| ---: | ---: | ---: | ---: | ---: |
| ARM_NEON | 2 |  8.22 ± 0.01 | 9.79 ± 0.00 | 1.191 |
|                      | 4 | 15.12 ± 0.01  | 18.25 ± 0.02 | 1.207 |
|                      | 8 | 28.01 ± 0.13 | 32.33 ± 0.26  | 1.154 |
| Zen4            | 1 |  6.56 ± 0.00  | 7.13 ± 0.11  |  1.087 |
|                      | 2 |  11.89 ± 0.00 | 13.35 ± 0.01  |  1.123 |
|                      | 4 |  19.37 ± 1.84  | 21.55 ± 0.86  |  1.113 |
| AVX2           | 2 | 5.06 ± 0.00   | 8.83 ± 0.00 | 1.745 |
|                     | 4 | 9.63 ± 0.00   |  16.28 ± 0.00 | 1.691 |
|                     | 8 |  17.45 ± 0.08  | 22.11 ± 0.00  | 1.267 |