Microsoft Surface Laptop Ultra Engineering Unit Features NVIDIA RTX Spark Arm SoC with 20 CPU Cores and 6144

An unreleased Microsoft Surface Laptop Ultra has been exposed, featuring an NVIDIA RTX Spark Arm architecture SoC. The engineering unit has 20 CPU cores and 6144 GPU cores. Initial tests ran an early graphics driver; after updating to the NVIDIA 616.00 preview driver, the built-in Blackwell GPU enabled CUDA support.

Under an 80W PL1 power limit (performance mode), the Cinebench 2024 CPU multi-core score was 1386 points, single-core 123 points; Cinebench 2026 CPU multi-core and single-core scores were 5771 and 540 points respectively. CPU performance is lower than the Apple M5 Pro chip and some x86 platforms.

The engineering unit exhibits early prototype flaws in power consumption, heat dissipation, and stability. After installing the new driver, standby power consumption rose significantly: from 7-8W to 12W in balanced mode, and reaching 23W in performance mode. In the Phoronix test suite's AI performance, no significant difference was observed between power modes. During testing, the device experienced regular crashes approximately every hour. In balanced and best power efficiency modes, CPU core power consumption reached up to 38W, with core temperatures hitting 98-100°C before the fan activated; in performance mode, core power was 44-50W at around 2.8GHz. The Blackwell GPU peak temperature was about 90°C, with operating frequencies generally maintained between 1550-1950MHz.

This Windows-on-Arm notebook achieves consistent GPU performance on battery and when plugged in. The model is equipped with features such as automatic backlight dimming when the user leaves and automatic wake-up via camera when the user approaches.