🧠 Llama.cpp + OpenCL (RX 6600 XT on Ubuntu 24.04)

• GPU: AMD RX 6600 XT
• Runtime: Mesa Rusticl (no ROCm needed)
• Model Format: .gguf (quantized)
• Server: llama-server HTTP + Web UI
• Client: Web browser or PowerShell Invoke-RestMethod

Based on this cmd history:

    4  sudo apt install rocm-opencl-dev
    5  mkdir rocm
    6  cd rocm
    7  wget https://repo.radeon.com/amdgpu-install/6.3.3/ubuntu/noble/amdgpu-install_6.3.60303-1_all.deb
    8  sudo apt install ./amdgpu-install_6.3.60303-1_all.deb
   11  sudo reboot
   16  cd rocm/
   18  sudo apt update
   19  sudo apt full-upgrade
   20  sudo apt install rocm-opencl-dev
   22  sudo apt install clinfo
   24  clinfo
   31  sudo apt install mesa-opencl-icd clinfo
   32  sudo nano /etc/drirc
   33  sudo reboot
   35  sudo clinfo | grep 'Device Name'
   36  mkdir oclLlama
   37  cd oclLlama/
   38  git clone https://github.com/ggerganov/llama.cpp
   39  cd llama.cpp
   46  make LLAMA_OPENCL=1
   47  sudo apt install cmake build-essential libclblast-dev ocl-icd-opencl-dev
   48  mkdir build
   49  cd bould
   50  cd build/
   51  cmake .. -DLLAMA_CLBLAST=on
   52  sudo apt install curl
   53  sudo apt install libcurl4-openssl-dev
   54  cmake .. -DLLAMA_CLBLAST=on
   55  cmake --build . --config Release -j$(nproc)
   59  ls -lh /home/facundo/oclLlama/llama.cpp/models/*.gguf
   60  cd ~/oclLlama/llama.cpp/models
   68  ls *.gguf
   69  ./bin/llama-server   --model /home/facundo/oclLlama/llama.cpp/models/phi-2.Q4_K_M.gguf   --host 0.0.0.0   --port 11434   --n-gpu-layers 100
   70  ls ..
   71  cd ..
   72  ls
   73  cd build/
 
here I uploaded the .gguf from my laptop
 
   74  ./bin/llama-server   --model /home/facundo/oclLlama/llama.cpp/models/phi-2.Q4_K_M.gguf   --host 0.0.0.0   --port 11434   --n-gpu-layers 100

Gepetto said:

# 1. Optional: ROCm was tried (not strictly needed with Rusticl)
sudo apt install rocm-opencl-dev
 
# 2. Mesa drivers + OpenCL ICD loader
sudo apt install mesa-opencl-icd clinfo
 
# 3. Confirm GPU visibility
clinfo | grep 'Device Name'
# → Should list RX 6600 XT
 
# 4. Get the source
mkdir -p ~/oclLlama
cd ~/oclLlama
git clone https://github.com/ggerganov/llama.cpp
cd llama.cpp
 
# 5. Install build deps
sudo apt install cmake build-essential \
  libclblast-dev ocl-icd-opencl-dev \
  libcurl4-openssl-dev
 
# 6. Build with OpenCL
mkdir build && cd build
cmake .. -DLLAMA_CLBLAST=on -DCMAKE_BUILD_TYPE=Release
cmake --build . --config Release -j$(nproc)
 
# 7. Download or upload a model
mkdir -p ~/oclLlama/llama.cpp/models
# (SCP from your laptop or download a .gguf file to /models/ dir)
 
# 8. Run the API server
./bin/llama-server \
  --model ~/oclLlama/llama.cpp/models/phi-2.Q4_K_M.gguf \
  --host 0.0.0.0 \
  --port 11434 \
  --n-gpu-layers 100

• http://ryzen-ubuntu.facundoitest.space:11434
• ✅ Built-in Web UI opens

Invoke-RestMethod -Uri "http://ryzen-ubuntu.facundoitest.space:11434/v1/completions" `
  -Method Post `
  -ContentType "application/json" `
  -Body '{
    "model": "phi-2.Q4_K_M.gguf",
    "prompt": "OpenCL advantages?",
    "max_tokens": 64
  }'

radeontop      # real-time GPU load
strings ./bin/main | grep -i clblast
ldd ./bin/main | grep -i opencl

sudo apt purge rocm-opencl-dev amdgpu-install