RTX 5090, 32GB VRAM top 2026 local LLM specs

VRAM is the non-negotiable bottleneck for LLMs; everything else is secondary to fitting model weights into the GPU buffer.

• –The NVIDIA RTX 5090 (32GB) is the 2026 value king, enabling 8-bit (Q8) quantization for 30B models with room for 32k+ token context windows in a single-slot solution.
• –24GB (RTX 3090/4090) remains the minimum floor for 30B models at 4-bit quantization, though memory bandwidth limitations are becoming more apparent compared to GDDR7.
• –Apple’s M4/M5 Ultra Mac Studio with 128GB+ unified memory is the superior choice for massive context windows or FP16 precision, sacrificing raw tokens-per-second for capacity and efficiency.
• –Dual-GPU setups (e.g., 2x RTX 5080) offer 32GB+ capacity but introduce power overhead and PCIe scaling complexities that favor single-card solutions where possible.
• –System RAM (64GB+) is essential for background tasks and context swapping but cannot compensate for insufficient VRAM without devastating performance penalties.