Mar 26, 2026

Best GPU for Local LLMs Under $1,500: The Decision That Determines Your Model Limits

At $1,500, you choose between a used RTX 4090 with 24 GB and 1,008 GB/s, or a new RTX 5080 with 16 GB and 960 GB/s. One gives you more VRAM. The other gives you a warranty. The choice determines which models you can run.

Andre

GPUAILLMs

1.0

The core trade-off

Used RTX 4090: 24 GB VRAM, 1,008 GB/s, ~$1,200, no warranty RTX 5080: 16 GB VRAM, 960 GB/s, ~$999, full warranty The 8 GB gap = the entire 35B model tier (Mixtral 8x7B, Qwen 32B, Command R)

For models under 16 GB (7B-13B at Q4), both cards perform similarly. The 5080 has slightly newer architecture (Blackwell) and GDDR7 efficiency, but the bandwidth is comparable. The decision only matters when you hit the 16 GB ceiling: the 4090 keeps going to 24 GB, the 5080 stops. On Ollama and llama.cpp, both cards use the same CUDA backend — the question is purely VRAM capacity versus budget.

2.0

Under $1,500 comparison

GPU	VRAM	BW	Price	Ecosystem	Warranty	Best For
Used RTX 4090	24 GB	1,008 GB/s	~$1,200	CUDA	None	Best all-around LLM GPU
RTX 5080	16 GB	960 GB/s	~$999	CUDA	Full	Best new card for 7B-13B
RX 7900 XTX	24 GB	960 GB/s	~$750	ROCm	Full	Cheapest new 24 GB

3.0

Token speed comparison

For models that fit in both cards, speeds are within 10% of each other. The 4090 edges ahead due to slightly higher bandwidth. The real difference is which models fit at all.

Model	RTX 4090 (24 GB)	RTX 5080 (16 GB)	RX 7900 XTX (24 GB)
Mixtral 8x7B Q4	~50 t/s	~48 t/s	~45 t/s
Qwen 32B Q4	~35 t/s	~33 t/s	~33 t/s
Llama 8B Q8	~100 t/s	~95 t/s	~90 t/s
Qwen 32B Q4 (~18 GB)	~35 t/s	Does not fit	~33 t/s

Speeds estimated at ~70% bandwidth efficiency. Actual varies by framework and batch size.

4.0

Which should you buy?

-Used RTX 4090: 24 GB runs everything up to 35B at Q4. Highest bandwidth at this price (1,008 GB/s). Accept used-market risk (no warranty).
-RTX 5080: 16 GB limited to models under 16 GB. GDDR7 efficiency, newest architecture. Full warranty, lower power (360 W).
-RX 7900 XTX: 24 GB new with warranty at $750. ROCm works for llama.cpp and Ollama. Leaves $750 budget unspent.

See RTX 5080 vs Used RTX 4090 for the deep-dive comparison, or Best GPU for Local LLMs for the full lineup. Use our VRAM Calculator to check exact memory requirements for your model and quantization.

FAQ

Frequently Asked Questions

Can I get an RTX 5090 under $1,500?

No. The RTX 5090 retails at $1,999 and rarely drops below that. Under $1,500, your best options are the used RTX 4090 or new RTX 5080.

Should I wait for prices to drop?

Used RTX 4090 prices have stabilized. The RTX 5080 is current-gen and unlikely to drop significantly. Buy when you need it - waiting only helps if a specific used-market dip happens.

Is the RX 7900 XTX worth considering at $1,500 budget?

It costs only $750 and leaves you $750 unspent. If you only need 24 GB, the 7900 XTX at $750 is better value than a used 4090 at $1,200. Spend the savings on RAM, SSD, or save it.

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