DGX Spark (GH200 480GB) vs RTX 3090 Ti 24GB for Local LLMs
The RTX 3090 Ti 24GB has about 102% more memory bandwidth (1,008 vs 500 GB/s). Batch-1 decode tracks bandwidth closely, so a model that fits both cards should decode roughly 102% faster on the RTX 3090 Ti 24GB. The DGX Spark (GH200 480GB) fits more of the catalog at Q4/8K — 66 vs 35 of 69 models (480 vs 24 GB VRAM). Largest model that fits the DGX Spark (GH200 480GB) but not the RTX 3090 Ti 24GB: DeepSeek-V4-Pro (861.6B). MSRP is $3,000 for the DGX Spark (GH200 480GB) vs $1,999 for the RTX 3090 Ti 24GB. MSRP is a launch list price, not live retail — Amazon prices move; click through for the current price. In the Q4/8K head-to-head below (51 shared models), the RTX 3090 Ti 24GB posts the higher tok/s in 44 rows vs 7. Methodology.