# Perplexity / KL-divergence statistics for Qwen3.8-27B

- Reference model: bf16
- Dataset: wiki.test.raw
- Chunks: 100
- Base PPL: 6.744 ± 0.10317
- llama.cpp build: b10896

### Summary

| Quant | PPL(Q) | PPL(Q)/PPL(base) | PPL(Q)-PPL(base) | Mean KLD | Mean Δp | RMS Δp | Same top-p |
| ----- | ----- | ----- | ----- | ----- | ----- | ----- | ----- |
| Q8_0 | 6.75142 ± 0.103316 | 1.00149 ± 0.000351 | 0.010043 ± 0.002378 | 0.000921 ± 6.7e-05 | -0.02 ± 0.006% | 0.977 ± 0.106% | 98.745 ± 0.07% |
| Q6_K_L | 6.73971 ± 0.103022 | 0.999752 ± 0.000524 | -0.001674 ± 0.003535 | 0.002399 ± 7.4e-05 | -0.027 ± 0.009% | 1.382 ± 0.058% | 97.698 ± 0.094% |
| Q6_K | 6.74361 ± 0.103111 | 1.00033 ± 0.00061 | 0.002233 ± 0.004113 | 0.00357 ± 0.000153 | -0.031 ± 0.01% | 1.599 ± 0.054% | 97.353 ± 0.101% |
| Q5_K_M | 6.75391 ± 0.103262 | 1.00186 ± 0.000762 | 0.012531 ± 0.00514 | 0.005287 ± 0.00017 | -0.091 ± 0.013% | 2.103 ± 0.081% | 96.871 ± 0.109% |
| Q5_K_S | 6.76193 ± 0.103379 | 1.00305 ± 0.000822 | 0.020546 ± 0.005547 | 0.006012 ± 0.000195 | -0.12 ± 0.014% | 2.199 ± 0.069% | 96.4 ± 0.117% |
| Q4_K_L | 6.76195 ± 0.103389 | 1.00305 ± 0.001104 | 0.02057 ± 0.007443 | 0.010581 ± 0.000197 | -0.099 ± 0.018% | 2.841 ± 0.067% | 95.451 ± 0.13% |
| Q4_1 | 6.76072 ± 0.103288 | 1.00287 ± 0.001291 | 0.019337 ± 0.008695 | 0.015787 ± 0.000324 | -0.113 ± 0.022% | 3.483 ± 0.085% | 94.51 ± 0.143% |
| Q4_K_M | 6.76446 ± 0.103309 | 1.00342 ± 0.001235 | 0.023082 ± 0.008317 | 0.013878 ± 0.000366 | -0.153 ± 0.02% | 3.254 ± 0.081% | 94.996 ± 0.137% |
| IQ4_NL | 6.76445 ± 0.103307 | 1.00342 ± 0.001293 | 0.023072 ± 0.008703 | 0.014962 ± 0.000371 | -0.172 ± 0.021% | 3.411 ± 0.079% | 94.784 ± 0.139% |
| Q4_K_S | 6.77046 ± 0.103353 | 1.00431 ± 0.001274 | 0.029081 ± 0.008578 | 0.015601 ± 0.000295 | -0.215 ± 0.022% | 3.472 ± 0.08% | 94.773 ± 0.139% |
| Q4_0 | 6.86425 ± 0.105544 | 1.01823 ± 0.001735 | 0.122867 ± 0.011843 | 0.026524 ± 0.000451 | -0.266 ± 0.028% | 4.536 ± 0.101% | 92.784 ± 0.162% |
| IQ4_XS | 6.78031 ± 0.103638 | 1.00578 ± 0.001437 | 0.03893 ± 0.009676 | 0.018841 ± 0.000471 | -0.208 ± 0.024% | 3.793 ± 0.079% | 94.141 ± 0.147% |
| IQ3_M | 6.92355 ± 0.105518 | 1.02702 ± 0.002104 | 0.182168 ± 0.014211 | 0.040647 ± 0.000622 | -0.847 ± 0.036% | 5.783 ± 0.11% | 91.055 ± 0.179% |
| Q3_K_L | 6.90279 ± 0.106406 | 1.02394 ± 0.002157 | 0.161412 ± 0.014737 | 0.043241 ± 0.000706 | -0.355 ± 0.036% | 5.685 ± 0.101% | 90.714 ± 0.182% |
| Q3_K_M | 7.03035 ± 0.109156 | 1.04286 ± 0.002543 | 0.288969 ± 0.01779 | 0.056425 ± 0.00088 | -0.609 ± 0.041% | 6.584 ± 0.116% | 89.812 ± 0.189% |
| IQ3_XS | 6.99622 ± 0.10673 | 1.0378 ± 0.002569 | 0.254844 ± 0.017398 | 0.058524 ± 0.00086 | -1.006 ± 0.042% | 6.846 ± 0.114% | 89.408 ± 0.193% |
| Q3_K_S | 7.08464 ± 0.110429 | 1.05092 ± 0.002747 | 0.343256 ± 0.019408 | 0.064792 ± 0.000983 | -0.6 ± 0.044% | 7.094 ± 0.126% | 88.953 ± 0.196% |
| IQ3_XXS | 7.05932 ± 0.107866 | 1.04716 ± 0.002906 | 0.317942 ± 0.019746 | 0.07388 ± 0.00114 | -1.251 ± 0.048% | 7.79 ± 0.134% | 88.51 ± 0.2% |
| Q2_K | 7.43849 ± 0.114518 | 1.10341 ± 0.004572 | 0.697107 ± 0.031501 | 0.161216 ± 0.002239 | -2.38 ± 0.07% | 11.408 ± 0.163% | 83.525 ± 0.232% |
| IQ2_M | 7.52818 ± 0.116097 | 1.11671 ± 0.004474 | 0.786799 ± 0.031377 | 0.149377 ± 0.002056 | -2.608 ± 0.067% | 11.051 ± 0.153% | 83.906 ± 0.23% |
| IQ2_S | 7.72954 ± 0.118009 | 1.14658 ± 0.005361 | 0.988156 ± 0.036929 | 0.209045 ± 0.002695 | -3.736 ± 0.08% | 13.257 ± 0.164% | 80.976 ± 0.246% |
| IQ2_XS | 8.025 ± 0.122332 | 1.19041 ± 0.005935 | 1.28362 ± 0.04144 | 0.24027 ± 0.002841 | -4.846 ± 0.086% | 14.572 ± 0.165% | 79.698 ± 0.252% |
| IQ2_XXS | 8.41042 ± 0.130004 | 1.24758 ± 0.006905 | 1.66904 ± 0.049626 | 0.283397 ± 0.003313 | -5.486 ± 0.092% | 15.735 ± 0.171% | 78.039 ± 0.259% |

### KLD percentile ladder

| Quant | Max | 99.9% | 99% | 95% | 90% | Median | 10% | 5% | 1% | 0.1% | Min |
| ----- | ----- | ----- | ----- | ----- | ----- | ----- | ----- | ----- | ----- | ----- | ----- |
| Q8_0 | 1.0809 | 0.040699 | 0.00706 | 0.002394 | 0.001448 | 0.000334 | 9e-06 | 2e-06 | -1e-06 | -8e-06 | -3e-05 |
| Q6_K_L | 0.973111 | 0.092973 | 0.01931 | 0.006956 | 0.004484 | 0.001173 | 2.3e-05 | 5e-06 | 0 | -4e-06 | -3.2e-05 |
| Q6_K | 3.01015 | 0.139894 | 0.030559 | 0.010436 | 0.006639 | 0.001579 | 3.7e-05 | 9e-06 | 0 | -3e-06 | -2e-05 |
| Q5_K_M | 2.84051 | 0.179695 | 0.051284 | 0.016652 | 0.010222 | 0.002319 | 5.9e-05 | 1.4e-05 | 1e-06 | -2e-06 | -3.5e-05 |
| Q5_K_S | 4.19186 | 0.204707 | 0.058225 | 0.019891 | 0.011923 | 0.002638 | 6.7e-05 | 1.7e-05 | 2e-06 | -1e-06 | -1.3e-05 |
| Q4_K_L | 2.23146 | 0.353113 | 0.102686 | 0.036515 | 0.02187 | 0.004622 | 0.000122 | 3e-05 | 3e-06 | -1e-06 | -1.1e-05 |
| Q4_1 | 4.48169 | 0.535538 | 0.15125 | 0.053299 | 0.032149 | 0.006836 | 0.000176 | 4.3e-05 | 5e-06 | -0 | -8e-06 |
| Q4_K_M | 6.50884 | 0.52521 | 0.142121 | 0.045992 | 0.027477 | 0.005795 | 0.000152 | 3.7e-05 | 3e-06 | -0 | -1.1e-05 |
| IQ4_NL | 5.86888 | 0.572585 | 0.148268 | 0.049484 | 0.030007 | 0.006205 | 0.00016 | 4.1e-05 | 4e-06 | -1e-06 | -1e-05 |
| Q4_K_S | 2.95896 | 0.534154 | 0.159605 | 0.054462 | 0.032237 | 0.006696 | 0.000178 | 4.5e-05 | 4e-06 | 0 | -6e-06 |
| Q4_0 | 4.82004 | 0.873295 | 0.263285 | 0.089089 | 0.054593 | 0.011859 | 0.000302 | 7.4e-05 | 8e-06 | 1e-06 | -1e-05 |
| IQ4_XS | 7.31304 | 0.646303 | 0.189096 | 0.064107 | 0.037538 | 0.007868 | 0.000206 | 5.5e-05 | 5e-06 | -0 | -2.5e-05 |
| IQ3_M | 3.71947 | 1.19807 | 0.405264 | 0.139634 | 0.084763 | 0.018335 | 0.000582 | 0.00015 | 1.7e-05 | 2e-06 | -1e-06 |
| Q3_K_L | 6.37739 | 1.27356 | 0.427362 | 0.15179 | 0.090328 | 0.019294 | 0.000469 | 0.000124 | 1.1e-05 | 1e-06 | -7e-06 |
| Q3_K_M | 6.22563 | 1.74283 | 0.582466 | 0.193088 | 0.116458 | 0.025449 | 0.000631 | 0.000151 | 1.6e-05 | 2e-06 | -2e-06 |
| IQ3_XS | 6.70819 | 1.54722 | 0.583696 | 0.205317 | 0.12211 | 0.026238 | 0.000848 | 0.000228 | 2.8e-05 | 4e-06 | -6e-06 |
| Q3_K_S | 6.36858 | 2.01934 | 0.657329 | 0.222889 | 0.135785 | 0.029351 | 0.000742 | 0.000188 | 1.9e-05 | 3e-06 | -0 |
| IQ3_XXS | 6.38787 | 2.27993 | 0.733495 | 0.2525 | 0.156451 | 0.033092 | 0.000938 | 0.000241 | 2.6e-05 | 4e-06 | -4e-06 |
| Q2_K | 8.55553 | 4.72795 | 1.66833 | 0.554146 | 0.340936 | 0.072722 | 0.00214 | 0.000494 | 5.3e-05 | 8e-06 | -0 |
| IQ2_M | 11.0817 | 4.06564 | 1.48056 | 0.513973 | 0.316133 | 0.068237 | 0.002261 | 0.000603 | 6.7e-05 | 1.1e-05 | -0 |
| IQ2_S | 11.4424 | 5.39947 | 1.96664 | 0.727937 | 0.448283 | 0.099357 | 0.003653 | 0.000949 | 0.000119 | 1.9e-05 | 4e-06 |
| IQ2_XS | 10.1463 | 5.58995 | 2.10155 | 0.839563 | 0.520093 | 0.123041 | 0.005352 | 0.001388 | 0.000189 | 2.8e-05 | 5e-06 |
| IQ2_XXS | 11.2416 | 6.63126 | 2.46692 | 0.972586 | 0.613898 | 0.147177 | 0.007022 | 0.001842 | 0.000237 | 3.7e-05 | 3e-06 |