System76’s Thelio Mira Linux desktop offers Ryzen 9000 CPUs, up to 192GB DDR5, and supports Nvidia RTX 5090 GPUs.

source https://www.techradar.com/pro/system76-is-charging-an-eye-popping-usd5299-for-an-nvidia-geforce-rtx-5090-gpu-upgrade-on-its-latest-pc-video-card-dwarves-ram-cost-in-latest-thelio-mira-linux-computer