Comparison
NVIDIA GeForce RTX 4090 vs NVIDIA DGX Spark for local LLMs
NVIDIA GeForce RTX 4090 (24GB usable, 1010 GB/s) vs NVIDIA DGX Spark (115.2GB usable, 273 GB/s) for local LLMs: capacity decides which models load at all, memory bandwidth decides the speed tier. Verdicts below are computed per model at each machine's best clean quant.
NVIDIA DGX Spark verdicts are beta: fit is physics and holds, but speed tiers aren't calibrated yet for that hardware class.
| Spec | NVIDIA GeForce RTX 4090 | NVIDIA DGX Spark |
|---|---|---|
| Type | NVIDIA GPU | NVIDIA prebuilt |
| Memory for models | 24 GB VRAM | 115.2 GB GPU-usable unified |
| Memory bandwidth | 1010 GB/s | 273 GB/s |
| Price | $1,599 MSRP | $4,699 base price |
| TDP | 450 W | — |
| Backends | CUDA · Vulkan | CUDA |
| Gaming (estimate) | 4K-class | — |
Specs as of 2026-07-08 / 2026-07-11 — sources on each product page. Gaming tier is estimated from FP32 compute, not a game benchmark.
What each can run, head to head
The 12 most-downloaded models we track, each graded at that machine's best clean-fit quant (llama.cpp, 8K context). Click a verdict for the full breakdown.
Affiliate link — we may earn a commission. Verdicts are computed before any link is attached.
Verdicts computed from published specs and measured GGUF sizes — how the math works.