Microsoft's developer-focused take on NVIDIA's new RTX Spark silicon arrives as a compact box rather than a laptop, pairing 128GB of unified memory with enough GPU horsepower to keep open-weight models in the 120B+ parameter range resident on-device. The Surface RTX Spark Dev Box was shown off at Build 2026 alongside the broader Surface refresh, aimed squarely at engineers who want to iterate on large models without renting cloud GPUs.
Under the lid sits NVIDIA's RTX Spark platform: a 20-core Arm CPU paired with a GPU carrying 6,044 CUDA cores and up to 128GB of unified memory shared between processor and graphics. Microsoft is quoting up to a petaflop of local AI throughput, enough to run inference on models with over 120 billion parameters without offloading layers to disk.
The chassis is unusual for a mini PC: an anodized aluminum 3D-printed body with 1,000 air vents milled into a grid pattern, formed as a flat slab perched on a narrower base. Microsoft says the design dissipates up to 100 watts of heat, though it has not confirmed whether the system is passively cooled or relies on fans inside the base. Port selection includes a USB Type-A and Ethernet jack on the bottom, with two USB Type-C, HDMI, and a 3.5mm headphone jack up top.
Out of the box, the dev box ships with Windows 11 tuned for development, with Visual Studio Code, GitHub Copilot, and WSL 2 preinstalled and configured. Microsoft has not published pricing, release timing, or full hardware specifications including storage options and exact power draw, with more details expected ahead of broader RTX Spark hardware launches later this year per the Windows developer blog.
