--- type: reference title: ik_llama.cpp on Dankserver (Ornith Q8_0) description: ikawrakow/ik_llama.cpp replaces upstream llama.cpp for frank-zealot on the RTX 3090. Q8_0 model, KV K default f16 / V q6_0 with Hadamard on V only (iq5_k is not a KV-cache type in this build; q8_KV crashes on this arch), split-mode none, speculative decoding disabled, 3 parallel slots x 163840 ctx, the Qwen-Sharp template rendered with --jinja, and explicit CPU-expert offload. Includes the mandatory CUDA/IQK FA_ALL_QUANTS build flags. tags: - ikllama - llamacpp - cuda - dankserver - moe - ornith - kv-cache - hadamard timestamp: 2026-08-26 --- # ik_llama.cpp on Dankserver (Ornith-1.5-35B-A3B CRACK) > **Active 2026-08-26.** `frank-zealot` switched from upstream > llama.cpp (b10121) to `ikawrakow/ik_llama.cpp` (commit `b166e269`) on the > RTX 3090. This page documents the build, the mandatory FA build flags, and > the MoE / CPU-offload runtime arguments. The model is `dealignai/Ornith-1.5-35B-A3B-UNCENSORED` (CRACK **Q8_0**), 35B-total / 3B-active MoE-dense hybrid with an MTP head in the GGUF (mmproj f16 vision encoder). Served as **three parallel 160000-context slots** (`PARALLEL=3`). Speculative decoding is **disabled**. See [[dealign-ornith-crack]] for the model runbook. ## Why ik_llama.cpp ik_llama.cpp is ikawrakow's llama.cpp fork with heavy CPU + CUDA optimizations, IQK/AVX-512 kernels, `--fit` auto-offload, and fast q8_KV cache. Dankserver is a CUDA (RTX 3090) + CPU-MoE-offload box, which is exactly the supported hybrid the fork targets. Only CPU and CUDA backends are fully functional; ROCm / Vulkan / Metal are unsupported upstream. ## Build recipe (CUDA 13.2 via staged pip toolkit) The system CUDA toolkit on Dankserver is **removed** (`nvidia-cuda-toolkit` is in `rc` state; no `/usr/local/cuda*`, no `/usr/bin/nvcc`). The CUDA 13.2 toolkit is installed via **pip** inside the vllm venv at `/home/dank/vllm/.venv/lib/python3.12/site-packages/nvidia/cu13/`. A staged, self-contained toolchain at `/home/dank/cuda13-stage` adds the unversioned `.so` aliases and static libs CMake needs. ```bash # 1. Clone a pinned ik_llama.cpp git clone https://github.com/ikawrakow/ik_llama.cpp.git /home/dank/ik_llama.cpp cd /home/dank/ik_llama.cpp git checkout b166e269 # the version this deployment was built from # 2. Configure (stage already symlinks nvcc/include/lib for cu13) cmake -B build \ -DCMAKE_BUILD_TYPE=Release \ -DGGML_CUDA=ON \ -DGGML_CUDA_FA_ALL_QUANTS=ON \ -DGGML_IQK_FA_ALL_QUANTS=ON \ -DCMAKE_CUDA_ARCHITECTURES=86 \ -DCMAKE_CUDA_COMPILER=/home/dank/cuda13-stage/bin/nvcc \ -DCUDAToolkit_ROOT=/home/dank/cuda13-stage \ -DGGML_NATIVE=ON # 3. Build cmake --build build --config Release -j 8 ``` ### ⚠️ MANDATORY: always include the FA all-quants flags > **Rule.** Any ik_llama.cpp build that serves a quantized KV cache > (q8_KV / q8_0 / Hadamard / any non-f16 KV) **MUST** be compiled with > BOTH: > - `-DGGML_CUDA_FA_ALL_QUANTS=ON` — compiles every K/V cache quant combo > into the **CUDA** FlashAttention kernels. Without it, CUDA FA only ships > a subset and **errors at runtime** telling you to recompile when a combo > (e.g. q8_KV + Hadamard V-cache) isn't present. The RTX 3090 keeps KV on > the GPU, so this is the flag that matters here. > - `-DGGML_IQK_FA_ALL_QUANTS=ON` — compiles all quant types (Q4_0/Q4_1/ > IQ4_NL on top of the always-on F16/Q8_0/Q6_0/BF16) into the **CPU/IQK** > FA kernels. Relevant because the MoE experts run on the CPU; the KV > cache that backs CPU-side attention uses the IQK FA path. > > These are the old "asymmetrical quants" compile-time gates. On a CUDA > host, omitting `GGML_CUDA_FA_ALL_QUANTS` is the #1 way to get a > "recompile with GGML_CUDA_FA_ALL_QUANTS" crash at load time. `GGML_NATIVE=ON` lets GCC target the host (the Ryzen 7 7700X is Zen4, so `-march=native` enables the AVX512 / VNNI IQK kernels automatically — verifiable with `system_info: AVX512_VNNI = 1` in the boot log). ### CUDA stage note `/home/dank/cuda13-stage` is the pip `cu13` toolkit plus the symlinks CMake's (CUDAToolkit) finder needs (`libcudart.so`, `libcublas.so`, `libcublasLt.so` and static `libcudadevrt.a`/`libcudart_static.a`). It also works around the CCCL CUDA version skew by defining `-DCCCL_DISABLE_CTK_COMPATIBILITY_CHECK` in `CMAKE_CUDA_FLAGS` (the pip package ships nvcc 13.2.78 but reports `CUDART_VERSION 13000`, which trips a strict header lint). Do not re-run configure without that flag or you get a hard compile error. ## Runtime configuration Files: `scripts/serve-frank-zealot.sh`, `scripts/frank-zealot.env`, `scripts/frank-zealot.service` in the repo. The service just calls the serve script; the env file holds all tunables. ### KV cache: K default f16 / V q6_0 + Hadamard (V only) - `CACHE_TYPE_K=f16` — K cache at the default full-precision f16 (passes `--cache-type-k f16`). No Hadamard on K. - `CACHE_TYPE_V=q6_0` — V cache at 6-bit k-quant (passes `--cache-type-v q6_0`). - `V_CACHE_HADAMARD=1` — `--v-cache-hadamard` on V only. The Hadamard transform preserves V quality at 6-bit; K is full-precision f16 and does not need it (`K_CACHE_HADAMARD=0`). Implemented for both CUDA (`ggml-cuda/hadamard.cu`) and CPU (IQK) paths. Flash-attention is **on by default**. > **KV cache type history on this build (`b166e269`):** > - `iq5_k` is **not** a KV-cache type — the cache whitelist is > `f32/f16/bf16/q8_0/q4_0/q4_1/iq4_nl/q5_0/q5_1/q6_0/q8_KV`; `iq5_*` only > exist as weight quants. `--cache-type-k iq5_k` throws `Invalid cache > type`. > - `q8_KV` **crashes** with a `ggml view` size assert > (`ggml.c:5427: data_size + view_offs > ggml_nbytes(view_src)`) on this > QWEN3MOE/MTP + multimodal arch — independent of PARALLEL/speculation. > - The deployment settled on K at default **f16** (full precision, no > Hadamard) with V at **q6_0 + Hadamard**. With 3 parallel slots at 163840 context the KV cache is large; keeping K at full precision f16 while quantizing only V (with Hadamard) is the chosen budget split. The GPU-side expert set stays reduced to fit (see the expert section). ### Split mode: none (single GPU) - `SPLIT_MODE=none` → `--split-mode none` (the default). Dankserver has a single RTX 3090 yet ik_llama rejects `--split-mode graph` on a box with a single device: > `llama error loading model: It is not possible to use split mode 'graph' > with less than 2 devices` So `graph` is **not** a harmless no-op on one GPU — it is a hard load error (this bit us on the first deploy and loop the service). It also still works with the `--override-tensor` expert pins. > **Lesson.** ik_llama `--split-mode graph` requires ≥2 devices. On a > single-GPU host you must use `none` (or `layer`, which also needs >1). > Do not assume `--split-mode graph` degrades gracefully on one GPU. ### Expert offload (MoE: CPU with a partial GPU slice) The expert-offload pattern from upstream llama.cpp carries over: the `--override-tensor` regex pins the sparse expert (`ffn_*_exps`) tensors to the CPU buft, leaving the output-adjacent blocks 35-40 on CUDA. On the Q8_0 model each ffn expert tensor is **272 MiB** (~4 tensor/block ≈ 1088 MiB/block). With `PARALLEL=3` the KV cache tripled, so most expert blocks are pinned to CPU; only blocks **35-40** (output-adjacent, latency- and quality-relevant) stay on CUDA. Full-attention blocks 3,7,11,15,19,23 have no exps and are untouched by the regex. - `OVERRIDE_EXPERT` — the layer-bounded regex listing the blocks whose experts stay on CPU: `(0|1|2|4|5|6|8|9|10|12|13|14|16|17|18|20|21|22| 24|25|26|27|28|29|30|31|32|33|34)`. Blocks 35-40 (and the always-on full-attention set) are left off the list so their experts load to CUDA. - `OVERRIDE_BUFT=CPU`. - `N_GPU_LAYERS=999` — ik_llama `-ngl` / `--gpu-layers` only accepts an integer (the literal `all` is rejected). 999 means "load as many tensor layers as possible", while the expert override still pins the listed exps to CPU. > **Fused MoE** (`fused_moe`, `fused_up_gate`, `fused_mmad`) is **on by > default** in ik_llama — there is no positive flag; only `-no-fmoe` > disables it. `only_active_experts` is also on by default. Confirmed in the > boot log for the running service. To move more experts back to the GPU later, drop more block numbers from `OVERRIDE_EXPERT` (each block is ~1088 MiB on Q8_0; verify `nvidia-smi` headroom first and keep ~2-3 GiB margin for KV/compute). With the 3-slot KV cache there is little headroom, so the default keeps only 35-40 on GPU. ### Qwen-Sharp chat template via --jinja `--chat-template-file` alone only stores the template text; ik_llama **does not** render a custom template as real Jinja unless `--jinja` is also given (`inputs.use_jinja ? common_chat_templates_apply_jinja : `). Without `--jinja` it warns it only supports "commonly used templates" and silently uses built-in handlers, dropping the Qwen-Sharp template's thinking / image / tool formatting. So the serve script passes both `--chat-template-file` and `--jinja` (gated on `USE_JINJA`, set to `1`). ### Speculative decoding: disabled (3 parallel slots) `SPEC_TYPE=none` (passed as `--spec-type none`). Speculative decoding is intentionally disabled because ik_llama **limits any speculative stage to a a single server slot**: with `--parallel 3` a configured spec stage hard-exits at load with > `ERR [load_model] Speculative decoding is currently limited to a single > server slot (-np 1).` / `n_parallel=3` This service keeps **3 parallel slots** (one per user family via `PARALLEL=3`), so speculative decoding cannot be used here. MTP stays disabled. The model is a low-parameter MoE (3B active of 35B) and does not need the speculation it would cost a slot for. > **Lesson.** Do not combine speculative decoding with `--parallel > 1` in > ik_llama. Either drop to `-np 1` (one slot) and keep a spec stage, or keep > multiple slots and set `SPEC_TYPE=none`. For a multi-user service the > extra slots win. ### Flash-attention + sampling Flash-attention is **on by default** in ik_llama (`flash_attn=true`), so no `-fa`/`--flash-attn` flag is needed. Sampling, thread, batch, context, and checkpoint tunables (`TEMPERATURE`, `TOP_K`, `TOP_P`, `MIN_P`, thread, `BATCH_SIZE`, `UBATCH_SIZE`, `CTX_SIZE`, `PARALLEL`, `CTX_CHECKPOINTS`, `NO_MMAP`) are unchanged and pass straight through. ## MoE / hybrid-arg reference (not in upstream llama.cpp) Several ik_llama knobs matter for a CPU-MoE offload host: | flag | meaning | our use | |------|---------|---------| | `--split-mode graph` | split tensors+graph across devices; strong for MoE; **requires 2+ devices** | single 3090 → use `none` | `-ooae` / `--offload-only-active-experts` | default ON: copy **only active** experts RAM→VRAM | keep ON (huge for A3B: few experts active) | | `-grt q8_0` | reduce type for inter-GPU data exchange | not needed (single GPU) | | `--fit` | auto-offload to fit VRAM | conflicts with `--override-tensor`; do not use together (runtime error) | | `-n-cpu-moe N` / `--cpu-moe` | keep MoE weights of first N / all layers on CPU | also conflicts with `--fit`; our `--override-tensor` is finer-grained | | `--fit-margin` | VRAM safety margin for `--fit` | only relevant with `--fit` | The current deployment uses `--override-tensor` (not `--fit` or `--n-cpu-moe`) for the expert offload, so the `--fit`-conflict rules do not apply. ## Rollback The previous runtime `upstream llama.cpp b10121` and its binary (`/home/dank/llama.cpp/build/bin/llama-server`) are **left untouched**. To rollback to the old stack, change `LLAMA_SERVER=` in `scripts/frank-zealot.env` back to that path and `CACHE_TYPE_K/V` back to `f16` with Hadamard off, and re-enable the ngram spec / `--spec-type` flags. The model file is not changed either way. ## See Also - [[dealign-ornith-crack]] — the Ornith Q6_K model run - [[Dankserver System Specs]] — the host - [[deployment]] — service-scoped git deploy ## Citations - [ikawrakow/ik_llama.cpp README](https://github.com/ikawrakow/ik_llama.cpp) — MoE offload guidance and the `--split-mode graph` + CPU-offload warning - [ik_llama.cpp serverAppConfigs-docs/build.md](https://github.com/ikawrakow/ik_llama.cpp/blob/main/docs/build.md) — build flags incl. `GGML_CUDA_FA_ALL_QUANTS` and `GGML_IQK_FA_ALL_QUANTS` - [ik_llama.cpp serverAppConfigs-docs/parameters.md](https://github.com/ikawrakow/ik_llama.cpp/blob/main/docs/parameters.md) — q8_KV (PR 208), K/V Hadamard options, `-cuda graphs=0` workaround, and `--split-mode graph` MoE note (PR 1080)