Microsoft Surface RTX Spark Dev Box (128GB) for local AI.
With 128 GB it runs Qwen3.8 27B (needs 22.7 GB). 90 models fit.
Memory128 GB
Shared between CPU and graphics.
Bandwidthunknown GB/s
Higher means faster answers. Not published.
PriceFrom about $6,000
As of 2026-10-16. Check before buying.
By memory option.
| Memory | Usable | Models that fit | Best three |
|---|---|---|---|
| 128 GB | 96 GB | 90 | Qwen3.8 27B (22.7 GB), K2 Horizon MoVA 36B-A4B (28.1 GB), Qwen3.5 27B (21.5 GB) |
Published speeds.
Measured by others, with sources. Not our tests.
No published speed found yet.
Short answers.
- What is the best local LLM for the Microsoft Surface RTX Spark Dev Box (128GB)?
- With 128 GB, Qwen3.8 27B (needs 22.7 GB, AA 33.7). 90 of 124 models fit.
- How much does the Microsoft Surface RTX Spark Dev Box (128GB) cost?
- From about $6,000 (as of 2026-10-16). 2026 prices are inflated by the memory-chip shortage; check before buying.
Specs from Microsoft – Surface RTX Spark Dev Box product page (2026-10-16). Prices are approximate and dated; 2026 prices are inflated by the memory-chip shortage.
# Microsoft Surface RTX Spark Dev Box (128GB) for local AI URL: https://insidethemachine.ai/machines/surface-rtx-spark-dev-box Type: NVIDIA AI box. Chip: NVIDIA RTX Spark Superchip. Memory: unified, options 128 GB. Bandwidth: unknown GB/s (Not published.). Spec source: https://www.microsoft.com/en-us/surface/devices/surface-rtx-spark-dev-box (2026-10-16). Price: from about $6,000 (2026-10-16, approximate). Status: announced. ## Which models fit | memory GB | usable GB | models that fit | best 3 | |---|---|---|---| | 128 | 96 | 90 | Qwen3.8 27B (22.7 GB), K2 Horizon MoVA 36B-A4B (28.1 GB), Qwen3.5 27B (21.5 GB) | ## Published speeds None found yet. Notes: Pre-order only, US only, on Microsoft.com. Microsoft says it ships in November 2026; no exact date. The graphics chip can use less than the full 128GB (Microsoft gives no number). ## Questions **What is the best local LLM for the Microsoft Surface RTX Spark Dev Box (128GB)?** With 128 GB, Qwen3.8 27B (needs 22.7 GB, AA 33.7). 90 of 124 models fit. **How much does the Microsoft Surface RTX Spark Dev Box (128GB) cost?** From about $6,000 (as of 2026-10-16). 2026 prices are inflated by the memory-chip shortage; check before buying.