Side-by-side simulation · recommended settings

DGX Spark 2 vs 2× RTX 5090 Local LLM Comparison

Two DGX Sparks are advantageous for ultra-large model loading, and two RTX 5090s are advantageous for CUDA processing speed within 64GB.

Choose devices and a model

Left deviceRight device

Model to run on both

Comparison mode

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Input length

Same 117output tokens. Only evidence-qualified acceleration is selected automatically; runtime formats are shown on each device.

Left

Ready

2× DGX Spark 256GB

First token4.8 to 12.3 seconds

Prefill334 ~ 865 tok/s

Decode18.5 ~ 29.6 tok/s

Press Start above to generate the same answer on both devices.

4-bit · 2-node setup0.0s · 0/117

Right

Ready

2× RTX 5090 64GB (PCIe)

First token3.5 to 7.3 seconds

Prefill576 ~ 1,244 tok/s

Decode5.1 ~ 5.2 tok/s

Press Start above to generate the same answer on both devices.

llama.cpp CUDA · Q4_K_M · GPU split into 2 pieces0.0s · 0/117

With these settings, 2× DGX Spark 256GB finishes the full answer About 2.0× faster.

Compare from input processing to completion of 117 token response.

Which one fits my needs?

Answer completion

2× DGX Spark 256GB

At the estimate midpoint, it finishes the same answer about 2.0× faster.

Prompt processing

2× RTX 5090 64GB (PCIe)

The estimated input-processing midpoint is higher at 910 tok/s.

Image and video generation

Check the media model

LLM speed does not tell you media-generation performance. Choose the image or video model and resolution separately.

Runtime

Settings for your hardware

4-bit · 2-node setup / llama.cpp CUDA · Q4_K_M · GPU split into 2 pieces. When runtime paths differ, the speed gap also includes software and model-format differences.

Estimated power draw

2× DGX Spark 256GB

Estimated LLM power draw is lower at about 380 W. Noise and physical size need a separate check.

Local pricing

2× DGX Spark 256GB is a complete system, 2× RTX 5090 64GB (PCIe) is the price for 2 GPU units. When comparing GPU units, the base unit cost must be added.

Before choosing hardware

Measure	2× DGX Spark 256GB	2× RTX 5090 64GB (PCIe)
Available fast memory	232GB	61GB
Memory bandwidth	546GB/s	3584GB/s
Estimated total time	14 s	28 s
Estimated sustained LLM load	about 380W	about 1100W
Korean price range (KRW)	1,904–2,060 × KRW 10,000	1,798–1,858 × KRW 10,000

2× DGX Spark 256GB details (Korean)

Set up this device Image and video preview

2× RTX 5090 64GB (PCIe) details (Korean)

Set up this device Image and video preview

Estimated ranges for one user. Multi-GPU and multi-device results depend on the runtime and interconnect.