Microsoft’s new Surface RTX Spark Dev Box offers up to 1 petaflop of AI compute and 128 GB of unified memory. The company says that is enough to run models of more than 120 billion parameters, with a one million-token context, on the machine itself.
The compact desktop is the first in a new Surface category for software developers. It is built around Nvidia’s RTX Spark superchip, which pairs a Blackwell RTX GPU with a Grace CPU. Microsoft pitches it for developers who want to prototype, fine-tune and run models at their desks instead of paying for cloud GPU instances. The aluminium chassis doubles as a heatsink, a choice meant to support long training jobs and large-model inference.
Set up for development
The box ships with Windows 11 Pro already configured. Dark mode is on, the taskbar is simplified, Widgets are gone and Do Not Disturb is enabled. Developer Mode is switched on, and PowerShell 7 is the default shell. Windows Subsystem for Linux 2 comes with GPU passthrough and CUDA support, and VS Code, GitHub Copilot, Git, Python and Node.js are installed from the start.
Microsoft’s own tools are part of the package. AI Toolkit for VS Code handles model conversion, fine-tuning and evaluation inside the editor. Windows ML with TensorRT and Windows Copilot Runtime handle local inference, and Microsoft Foundry is meant to connect local prototyping to production deployment.
On security, the device uses Secured-core PC architecture, BitLocker encryption and Microsoft Defender, in line with Microsoft’s Zero Trust approach. Business customers can manage it through Entra ID and Intune.
Andrew Hill, corporate vice president for Surface product, described the thinking. “Development today means longer-running jobs, larger models and a growing need to prototype and iterate locally rather than paying for every cloud call,” he said. The Dev Box launched alongside the Surface Laptop Ultra. Hill said the two are “built specifically for makers,” with different form factors and the same aim of giving developers more choice in where and how they build.
