ROCm on a Radeon RX 6800 XT, maximum frustration when installing on Ubuntu 26 to build llama.cpp or use ComfyUi
Hello everyone,
since some days I try to install a llama.cpp and ComfyUi instance to use with my Radeon Rx 6800 XT. Theoretically the GPU has enough performance for the stuff I want to do. But it seems like I am not able to use:
- flash-attention
- mtp architecture
- unified kv-cache
- v-cache compression to Q8_0 or Q4_0
**without a working ROCm setup**
I am mainly using Hermes agent with a 64k context windows (it's the lower limit). I am sure that the root cause is the missing ROCm installation on my system but I tried several approaches and I told Hermes to setup it up itself. Neither of us made it. Can someone tell me:
- If the Radeon RX 6800 XT supports ROCm and flash-attention at all?
- A clean approach to install it on my Linux system
These are my specific system details:
OS: Ubuntu 26
CPU: Ryzen 9 7950 X3D
GPU: XFX Radeon RX 6800 XT Merc 319
RAM: 32GB DDR5
Model: Qwen 3.6 A3B MoE