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Best AMD vs Best NVIDIA GPU for Local LLMs

AMD vs NVIDIA for local LLMs: RX 7900 XTX (24 GB, ROCm) vs RTX 5090 (32 GB, CUDA) and RTX 4090 (24 GB, CUDA). Software ecosystem, VRAM, bandwidth, and which to choose.

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April 24, 2026

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GPU Comparison

AMD vs NVIDIA for Local LLMs

AMD offers the cheapest new 24 GB card (RX 7900 XTX) with ROCm support. NVIDIA offers the broadest software ecosystem (CUDA), the highest bandwidth, and the only 32 GB consumer option (RTX 5090). Choose based on your software comfort, VRAM needs, and budget.

Radeon RX 7900 XTX

Best AMD

Radeon RX 7900 XTX

24 GB — Cheapest New 24 GB

GeForce RTX 4090

Best Used NVIDIA

GeForce RTX 4090

24 GB — CUDA Value

$1,599.99Check Price
GeForce RTX 5090

Best NVIDIA

GeForce RTX 5090

32 GB — Top Tier

$1,999.99Check Price

01 / Specifications

Spec by Spec

Specification
Radeon RX 7900 XTX
GeForce RTX 4090
GeForce RTX 5090
VRAM
24 GB GDDR6
24 GB GDDR6X
32 GB GDDR7
Bandwidth
960 GB/s
1,008 GB/s
1,792 GB/s
Ecosystem
ROCm
CUDA
CUDA
Price
$750 new
~$1,200 used
$1,999 new
TDP
355 W
450 W
575 W
Warranty
Full
None (used)
Full
Max Model (full GPU)
35B at Q4
35B at Q4
70B at Q4

02 / Ecosystem

ROCm vs CUDA for Local LLMs

AMD and NVIDIA take fundamentally different approaches to software. ROCm is improving but trails CUDA in breadth of support and Windows compatibility.

AMD (ROCm)

  • llama.cpp

    Full support, all quantizations

  • Ollama

    AMD GPU support

  • vLLM

    ROCm backend

  • Linux-first

    Windows less mature

NVIDIA (CUDA)

  • Every framework

    First-class target for all LLM tools

  • FP8 + Flash Attention

    Out of the box

  • Windows + Linux

    Both platforms seamless

  • Only 32 GB consumer option

    RTX 5090 for unrestricted model access

03 / Strengths & Weaknesses

Pros and Cons

Radeon RX 7900 XTX — Strengths

Strengths

  • Cheapest new GPU with 24 GB VRAM
  • 960 GB/s bandwidth competitive with RTX 4090
  • ROCm support is improving rapidly across major frameworks
  • Good value for 70B models at aggressive quantization

Weaknesses

  • ROCm ecosystem still lags behind CUDA in tooling and support
  • Some quantization formats and optimizations arrive later
  • GDDR6 is slightly slower than GDDR6X on bandwidth

GeForce RTX 4090 — Strengths

Strengths

  • 1,008 GB/s bandwidth — faster than the new RTX 5080
  • 24 GB VRAM opens up 70B-class models
  • Full CUDA + FP8 + Flash Attention support
  • Significant discount over buying new

Weaknesses

  • No warranty on used cards
  • 450 W TDP needs a strong PSU and good cooling
  • Risk of degraded hardware from mining or heavy use

GeForce RTX 5090 — Strengths

Strengths

  • 32 GB VRAM fits most useful models at usable quantizations
  • 1,792 GB/s bandwidth — fastest consumer GPU for inference
  • Full CUDA ecosystem support with no configuration headaches
  • FP8 and Flash Attention 2 support for faster inference

Weaknesses

  • 575 W TDP demands a 1,000 W PSU and strong cooling
  • Most expensive consumer GPU on the market
  • Overkill if you only run 7B-13B models

04 / Verdict

The Bottom Line

AMD Route

Radeon RX 7900 XTX

$750 new, 24 GB, warranty. Best if you run Linux and your frameworks support ROCm. Unbeatable new-card value for 24 GB.

Used NVIDIA

GeForce RTX 4090

~$1,200, 24 GB, CUDA. Best value for 24 GB with full software support. Outperforms every new card in its price range.

Premium NVIDIA

GeForce RTX 5090

$1,999, 32 GB, CUDA. Only option for 70B models at Q4 without offloading. Unrestricted model access.

For more details, see our Best AMD GPU, Best NVIDIA GPU, and main hub pages.

05 / Related

More Comparisons

Frequently Asked Questions

Is AMD ROCm good enough for local LLMs?
For standard inference with llama.cpp and Ollama: yes. For cutting-edge quantization, custom kernels, and PyTorch training: CUDA is more reliable. ROCm is improving rapidly but still trails CUDA in breadth of support.
Does AMD have a 32 GB consumer GPU?
No. AMD caps at 24 GB for consumer cards. If you need 32 GB, the RTX 5090 is the only option. This is a hard ceiling for AMD users who want to run 70B models at Q4.
Is the RX 7900 XTX a good value for LLMs?
Yes — it is the cheapest new 24 GB card. At $750 with a warranty, it offers strong value against a used RTX 4090 ($1,200, no warranty). The trade-off is ROCm software maturity.
Should I switch from NVIDIA to AMD for LLMs?
Only if you are comfortable troubleshooting GPU issues and your frameworks work on ROCm. CUDA has less friction. If you want everything to work immediately, stay with NVIDIA.

Looking for specific GPU recommendations? Our main guide covers every budget and VRAM tier.

Best GPU for Local LLMs →
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