Nvidia's mod runtime gives Blackwell Ultra by default. RTX Spark gets Medium.
Nvidia's RTX Remix runtime now recognises RTX Spark and hands it Medium graphics settings and DLSS at its Performance setting by default. The change arrived in a commit titled "Apply RTX Spark defaults for Auto graphics settings", written by an author with an nvidia.com address at 18:15:58 UTC on October 9 and read at 21:48 UTC on October 10.
Nvidia's own code comment says the core count differs between RTX Spark SKUs, which is why detection ignores it. Image: Nvidia
Nvidia wrote the documentation for it in the same commit, and the sentence is flat: "On RTX Spark, Auto graphics selection defaults to Medium, and Auto DLSS selection defaults to Performance. Per-GPU graphics and DLSS overrides take precedence over these defaults." The runtime logs the decision as "RTX Spark detected, setting default graphics settings to Medium".
The ladder it steps around ends at Ultra
The runtime had a way of guessing before this. When the graphics preset is set to Auto, the runtime reads the GPU architecture and picks from a ladder written into the same file: Turing gets Low, Ampere gets Medium, Ada gets High, and Blackwell gets Ultra, each with a log line of its own. Cards from other vendors get Low, and anything with 8 GiB or less drops a rung.
RTX Spark's graphics processor is Blackwell, and the ladder puts Blackwell on Ultra. The new branch runs first and returns before the ladder is ever reached, which leaves the same architecture two rungs lower than a discrete Blackwell card. Nvidia's commit message describes what it is detecting: "RTX Spark (N1X: ARM64 CPU with an integrated Blackwell GPU and unified memory)".
Detection ignores the core count on purpose
The test is narrow. Nvidia's documentation says it "requires Vulkan to report an NVIDIA integrated GPU and NVAPI to identify the same adapter by LUID as an integrated Blackwell GPU", and then adds a line that is doing real work: "Core count does not affect detection." A comment in the new code explains why the runtime still writes the number down, saying it is "logged for diagnostics only, because the core count differs between RTX Spark SKUs".
Memory is handled separately. With the preset on Auto, low memory mode switches on when the Vulkan device-local heaps total 8 GiB or less, and off otherwise, which means an RTX Spark machine with plenty of unified memory keeps the Medium default without the extra reduction. The commit also brings a unit test file of just under 300 lines, so the behaviour is pinned rather than incidental.
What this is a default for
RTX Remix is the runtime behind Nvidia's path-traced remasters of older games, which is about the heaviest thing a GPU can be asked to draw, and a preset is a starting point a user can change. Nothing in the commit says RTX Spark machines ship with Remix, or that any released build carries this: the newest tagged release of the toolkit is remix-1.5.2 from June 16, and this is a change on the development branch.
It is still Nvidia writing down, in its own repository, what it expects one of its own designs to manage in a mod runtime Nvidia also owns, which is not something a specification table ever says. The commit lands alongside the Arm64 rebuilds Nvidia pushed through its RTX game SDKs in the eight days before RTX Spark, and it is a change on the development branch rather than anything a player can switch on.
