I benchmarked 21 Qwen3.8 27B variants on 16GB VRAM

After Qwen3.8 27B came out, I decided to benchmark the models that could fit in my GPU (RTX 5080) on my actual code (C code), the results were not completely unexpected but some quants were definitely underwhelming.

TLDR: Best overall: bartowski/Qwen3.8-27B-IQ4_XS. Best uncensored: huihui-ai/Huihui-Qwen3.8-27B-abliterated-UD-IQ4_XS. For a bit more context: ISTA-DASLab/Qwen3.8-27B-GSQ-RCO-IQ3_S or uncensored: huihui-ai/Huihui-Qwen3.8-27B-abliterated-GSQ-RCO-IQ3_S-mtp

• edit1: added TheWegemann/Qwen3.8-27B-LowGPU-uncensored-NoMTP-IQ3XXXS, bartowski/Qwen3.8-27B-IQ3_XS, prism-ml/Ternary-Bonsai-27B-Q2_g64 and magiccodingman/Qwen3.8-27B-Quark-MXFP4-UD-Q4_K_S-Unsloth
• edit2: added unsloth/Qwen3.8-27B-UD-IQ3_S and ISTA-DASLab/Qwen3.8-27B-GSQ-RCO-IQ3_S
• edit3: added magiccodingman/Qwen3.8-27B-MQ-IQ2_M_1 and huihui-ai/Huihui-Qwen3.8-27B-abliterated-UD-IQ3_S
• edit4: added AtomicChat/Qwen3.8-27B-AD-IQ4_XS-IQ3_S
• edit5: added IvanKrastevAdventics/qwen3.8-27b-awq-int4-q4_0 (gguf of cyankiwi/qwen3.8-27b-awq-int4)
• edit6: added the updated bartowski/Qwen3.8-27B-IQ4_XS and bartowski/Qwen3.8-27B-IQ3_XXS
• edit7: added bartowski/Qwen3.8-27B-Q3_K_M, Thireus/09ae8ba_22b6bb2 and Thireus/09ae8ba_248b31b
• edit8: removed all MTP heads from the GGUF size for a more fair comparison. added bartowski/Qwen3.8-27B-IQ2_S
• edit9: added huihui-ai/Huihui-Qwen3.8-27B-abliterated-GSQ-RCO-IQ3_S-mtp
• edit10: added mradermacher/Eintopf-Qwen3.8-27B.i1-IQ3_M and hitsfmdj/Qwen3.8-27B-4.2BPW-16GB
• edit11: added Joakimpalm-Zen/Qwen3.8-27B-GSQ-RCO-IQ3_S-recovered
• edit12: added Mia-AiLab/Qwen3.8-27B-EXL3-3.5bpw and turboderp/SC_3.00bpw_H4_V4
• edi13: added prism-ml/Ternary-Bonsai-2-27B-PQ2_0 and prism-ml/Ternary-Bonsai-2-27B-PTQ1_0, replaced prism-ml/Ternary-Bonsai-27B-Q2_g64 with prism-ml/Ternary-Bonsai-27B-PQ2_0
• edit14: added Bucoid/Qwen3.8-27B-Heretic-Ara-iq4_xs-3.0
• edit15: added agentionai/Qwen3.8-27B-AP-IQ3_S, agentionai/Qwen3.8-27B-AP-IQ4_XS and RonnieOps/Qwen3.8-27B-IQ4_XS-fullvocab-E3. This is probably the final edit as Qwen4 27B will likely come out soon.
• edit16: added byteshape/Qwen3.8-27B-IQ4_XS-3.84bpw and byteshape/Qwen3.8-27B-IQ3_S-3.23bpw. Again, probably the last edit.

(sorted by Mean KLD)

|Model|Mean KLD|Same top p|GGUF size (without MTP)|
|:-|:-|:-|:-|
|prism-ml/Ternary-Bonsai-27B-PQ2\_0|1.289582 ± 0.008684|82.849 ± 0.118 %|6.7GiB|
|prism-ml/Ternary-Bonsai-2-27B-PQ2\_0|1.096134 ± 0.007705|84.596 ± 0.113 %|6.7GiB|
|prism-ml/Ternary-Bonsai-2-27B-PTQ1\_0|1.095914 ± 0.007703|84.582 ± 0.113 %|5.5GiB|
|sdkyuan/qwen38-27b-qat-q2\_0|0.893177 ± 0.006948|85.727 ± 0.110 %|8.2GiB|
|bartowski/Qwen3.8-27B-IQ2\_Sbartowski/Qwen3.8-27B-IQ2\_S (NEW)|0.784060 ± 0.006457|87.016 ± 0.105 %|8.7GiB|
|ISTA-DASLab/Qwen3.8-27B-GSQ-RCO-IQ2\_XS|0.767174 ± 0.006291|86.166 ± 0.108 %|7.8GiB|
|TheWegemann/Qwen3.8-27B-LowGPU-uncensored-NoMTP-IQ3XXXS|0.514311 ± 0.004864|89.023 ± 0.098 %|8.9GiB|
|ISTA-DASLab/Qwen3.8-27B-GSQ-RCO-IQ2\_S|0.512614 ± 0.004909|88.802 ± 0.099 %|8.6GiB|
|empero-ai/Qwen3.8-27B-Ridge-3.7bpw|0.475767 ± 0.004483|89.612 ± 0.096 %|11.4GiB|
|magiccodingman/Qwen3.8-27B-Quark-MXFP4-UD-Q4\_K\_S-Unsloth|0.419585 ± 0.004076|89.661 ± 0.095 %|13.1GiB|
|ISTA-DASLab/Qwen3.8-27B-GSQ-RCO-IQ3\_XXS|0.379222 ± 0.003992|90.270 ± 0.093 %|9.4GiB|
|unsloth/Qwen3.8-27B-UD-Q2\_K\_XL (UD2)|0.350861 ± 0.003745|90.626 ± 0.091 %|9.6GiB|
|byteshape/Qwen3.8-27B-IQ3\_S-3.23bpw|0.345563 ± 0.003703|90.868 ± 0.090 %|10.1GiB|
|mradermacher/Eintopf-Qwen3.8-27B.i1-IQ3\_M|0.318143 ± 0.003139|91.471 ± 0.087 %|11.7GiB|
|bartowski/Qwen3.8-27B-IQ3\_XXS (NEW)|0.300480 ± 0.003345|91.511 ± 0.087 %|11.3GiB|
|unsloth/Qwen3.8-27B-UD-IQ3\_XXS (UD2)|0.268594 ± 0.002971|91.951 ± 0.085 %|10.8GiB|
|magiccodingman/Qwen3.8-27B-MQ-IQ2\_M\_1|0.256808 ± 0.002861|92.056 ± 0.085 %|10.9GiB|
|DavidAU/Qwen3.8-27B-Cold-Fusion-GAIN-V1.1-NM-DAU-NEO-MAX-NEO-MTP-IQ3\_M|0.251270 ± 0.002702|92.315 ± 0.083 %|13.1GiB|
|huihui-ai/Huihui-Qwen3.8-27B-abliterated-UD-IQ3\_S|0.249650 ± 0.002841|92.016 ± 0.085 %|10.8GiB|
|bartowski/Qwen3.8-27B-IQ3\_XS (OLD)|0.238656 ± 0.002627|92.312 ± 0.083 %|12.2GiB|
|hitsfmdj/Qwen3.8-27B-4.2BPW-16GB|0.222090 ± 0.002570|92.552 ± 0.082 %|11.7GiB|
|esatapedico/Qwen3.8-27B-NVFP4-MTP-LOW|0.220796 ± 0.002631|92.339 ± 0.083 %|14.3GiB|
|unsloth/Qwen3.8-27B-UD-IQ3\_S (UD3)|0.218522 ± 0.002591|92.399 ± 0.083 %|10.9GiB|
|turboderp/SC\_3.00bpw\_H4\_V4 (exllama3)|0.205712 ± 0.002509|92.573 ± 0.082 %|11.9GiB|
|jrell/Qwen3.8-27B-i1-IQ4\_XS-GGUF-Smaller|0.194459 ± 0.002242|93.049 ± 0.080 %|12.4GiB|
|agentionai/Qwen3.8-27B-AP-IQ3\_S|0.193041 ± 0.002352|92.995 ± 0.080 %|10.9GiB|
|orcarouter/Qwen3.8-27B-Uncensored-Q3\_K\_L|0.192312 ± 0.002294|92.726 ± 0.081 %|13.4GiB|
|bartowski/Qwen3.8-27B-Q3\_K\_M (NEW)|0.191103 ± 0.002369|92.823 ± 0.081 %|12.3GiB|
|mudler/Qwen3.8-27B-APEX-I-Mini|0.190209 ± 0.002354|93.012 ± 0.080 %|12.6GiB|
|Joakimpalm-Zen/Qwen3.8-27B-GSQ-RCO-IQ3\_S-recovered|0.178882 ± 0.002102|93.110 ± 0.079 %|11.0GiB|
|huihui-ai/Huihui-Qwen3.8-27B-abliterated-GSQ-RCO-IQ3\_S-mtp|0.178715 ± 0.002200|92.949 ± 0.080 %|11.0GiB|
|Thireus/09ae8ba\_22b6bb2 (ikllama.cpp quality 41.39%)|0.178290 ± 0.002202|93.115 ± 0.079 %|11.0GiB|
|ISTA-DASLab/Qwen3.8-27B-GSQ-RCO-IQ3\_S|0.175223 ± 0.002129|93.024 ± 0.080 %|11.0GiB|
|Mia-AiLab/Qwen3.8-27B-EXL3-3.5bpw (exllama3)|0.149827 ± 0.001936|93.735 ± 0.076 %|14.1GiB|
|unsloth/Qwen3.8-27B-UD-Q3\_K\_XL (UD2)|0.147186 ± 0.001809|93.734 ± 0.076 %|12.2GiB|
|unsloth/Qwen3.8-27B-UD-Q3\_K\_XL (UD3)|0.142647 ± 0.001860|93.789 ± 0.076 %|11.9GiB|
|byteshape/Qwen3.8-27B-IQ4\_XS-3.84bpw|0.131976 ± 0.001690|93.852 ± 0.075 %|12.0GiB|
|IvanKrastevAdventics/qwen3.8-27b-awq-int4-q4\_0|0.112990 ± 0.001558|94.171 ± 0.073 %|14.4GiB|
|AtomicChat/Qwen3.8-27B-AD-IQ4\_XS-IQ3\_S|0.111713 ± 0.001492|94.527 ± 0.071 %|13.2GiB|
|Bucoid/Qwen3.8-27B-Heretic-Ara-iq4\_xs-3.0|0.097572 ± 0.001341|94.651 ± 0.070 %|13.0GiB|
|Bucoid/Qwen3.8-27B-Uncensored-IQ4\_XS\_4BPW|0.091447 ± 0.001261|94.774 ± 0.070 %|12.8GiB|
|huihui-ai/Huihui-Qwen3.8-27B-abliterated-UD-IQ4\_XS|0.082871 ± 0.001205|94.981 ± 0.068 %|13.1GiB|
|unsloth/Qwen3.8-27B-UD-IQ4\_XS (UD3)|0.075626 ± 0.001097|95.258 ± 0.067 %|13.3GiB|
|agentionai/Qwen3.8-27B-AP-IQ4\_XS|0.073386 ± 0.001075|95.386 ± 0.066 %|13.0GiB|
|Thireus/09ae8ba\_248b31b (llama.cpp 49.75%)|0.063904 ± 0.000967|95.687 ± 0.064 %|13.3GiB|
|jpetrina/Qwen3.8-27B-IQ4\_XS-pure|0.061984 ± 0.000917|95.551 ± 0.065 %|13.3GiB|
|RonnieOps/Qwen3.8-27B-IQ4\_XS-fullvocab-E3|0.058278 ± 0.000886|95.773 ± 0.063 %|14.1GiB|
|bartowski/Qwen3.8-27B-IQ4\_XS (OLD)|0.056482 ± 0.000856|95.835 ± 0.063 %|14.3GiB|
|bartowski/Qwen3.8-27B-IQ4\_XS (NEW)|0.055415 ± 0.000849|95.850 ± 0.062 %|14.2GiB|
|unsloth/Qwen3.8-27B-UD-Q4\_K\_XL (UD3) *(can't fit)*|0.029844 ± 0.000476|96.921 ± 0.054 %|16.1GiB|
|unsloth/Qwen3.8-27B-UD-Q4\_K\_XL (UD2) *(can't fit)*|0.028026 ± 0.000432|96.988 ± 0.054 %|16.4GiB|

https://preview.redd.it/g9isjm0d04sh1.png?width=5355&format=png&auto=…

Hope this helps other VRAM starved people like me :)