RTX 4090
The 'expensive' GPU came out cheaper — we rented both to find out
We rented an A100 and an H100 back to back: the pricier card cost less per training run because it finished in half the time. Plus honest notes from the AI Engineer World's Fair floor, and a Qwen 3.7 open-weights status check.
RTX 5090 Benchmarks: 5090 vs 4090 vs Used 3090 (2026)
5090 community benches across 4K-131K context, prompt-processing tables, 5090-vs-4090 upgrade math, and InsiderLLM's firsthand 3090 honest-value anchor.
RTX 4090 vs Used RTX 3090 for Local AI: Which to Buy in 2026
Both have 24GB VRAM. One costs about twice as much. RTX 4090 vs used RTX 3090 — real benchmarks, real prices, and who should buy which for local AI.
What Can You Actually Run on 24GB VRAM?
Qwen 3.5 27B at Q4 fits in 17GB with 64K+ context. 70B at Q3 with limited context. Flux at full FP16. RTX 3090 at $1,200 vs 4090 at $2,250—every model that fits and which GPU to buy.