Side-by-side simulation · recommended settings

DGX Spark vs RTX 5090: Which fits your local LLM?

If you need a large model, start with configurations that fit Spark's 128GB memory. If the model fits the 5090's 32GB, compare speed with the same model and input, and include the cost of the PC around the GPU.

Choose devices and a model

Comparison mode
Expand comparison settings

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

Left

Ready

DGX Spark 128GB

First token2.7 to 4.9 seconds
Prefill839 ~ 1,535 tok/s
Decode16.7 ~ 23.4 tok/s

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

llama.cpp · Q4_K_M0.0s · 0/117

Right

Ready

RTX 5090 32GB

First token0.46 to 0.94 seconds
Prefill4375.9 ~ 9044.5 tok/s
Decode127.7 ~ 263.9 tok/s

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

Strata 0.1.41 · IQ3_S · MTP-6 · INT8 KV · SSD PLE0.0s · 0/117

With these settings, RTX 5090 32GB finishes the full answer About 8.1× faster.

Compare from input processing to completion of 117 token response.

Which one fits my needs?

Answer completion

RTX 5090 32GB

At the estimate midpoint, it finishes the same answer about 8.1× faster.

Prompt processing

RTX 5090 32GB

The estimated input-processing midpoint is higher at 6,710 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

llama.cpp · Q4_K_M / Strata 0.1.41 · IQ3_S · MTP-6 · INT8 KV · SSD PLE. When runtime paths differ, the speed gap also includes software and model-format differences.

Estimated power draw

DGX Spark 128GB

Estimated LLM power draw is lower at about 190 W. Noise and physical size need a separate check.

Local pricing

DGX Spark 128GB is the price of finished product, RTX 5090 32GB is the price of GPU separately. For individual GPUs, you need to add the cost of the main body before comparing.

Before choosing hardware

MeasureDGX Spark 128GBRTX 5090 32GB
Available fast memory116GB30.5GB
Memory bandwidth273GB/s1792GB/s
Estimated total time9.8 s1.2 s
Estimated sustained LLM loadabout 190Wabout 620W
Korean price range (KRW)952–1,030 × KRW 10,000899–929 × KRW 10,000
DGX Spark 128GB details (Korean)
RTX 5090 32GB details (Korean)

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