What Microsoft actually released
Microsoft's GDK sample, "AMD FSR Upscaling 4", is dated November 6, 2026. It requires the Microsoft Game Development Kit October 2025 or later, which is a developer prerequisite, not a consumer update. The sample demonstrates FSR Upscaling version 4.1.2 in two variants, Full and Lite. Lite is described as a highly optimized model less than half the size of the original INT8 model, built for lower-class hardware.
The Visual Studio solution targets both Gaming.Xbox.Scarlett.x64 (Xbox Series X|S) and x64 (Windows PC). Developers can cycle between FSR4 Full, FSR4 Lite and FSR3 at runtime on Xbox with the D-pad Left button. The sample also has toggles for sharpening, scaling mode and particle count.
This is a developer demonstration. It does not mean FSR 4.1.2 is already in retail Xbox games. AMD's October 20 announcement only said FSR Upscaling 4.1 on Xbox Series X|S was "coming soon". It was part of a wider rollout to Radeon RX 6000 cards, Ryzen AI Max and Ryzen AI 9 laptops, and Ryzen Z2 handhelds.
The numbers
Microsoft's table lists upscaler-pass cost only, not whole-frame cost, and says the figures are subject to change.
| Console | Model | Output | Time |
|---|---|---|---|
| Series X | Lite | 1440p | 1.29 ms |
| Series X | Lite | 4K | 2.75 ms |
| Series X | Full | 1440p | 1.95 ms |
| Series X | Full | 4K | 3.86 ms |
| Series S | Lite | 1080p | 1.9 ms |
| Series S | Lite | 1440p | 3.4 ms |
| Series S | Full | 1080p | 2.9 ms |
| Series S | Full | 1440p | 5.2 ms |
Digital Foundry's Rich Leadbetter ran the PC build of the sample on an RX 6700 XT, in the DF Direct Weekly episode of November 9. French outlet Menow reports that Digital Foundry did not run the Xbox library on PC and instead compares its Windows measurements with the console's published times. The reported results:
- Full model, 4K: about 5.0 ms on the RX 6700 XT, sometimes 5.2 ms. Microsoft lists 3.86 ms for Series X.
- With sharpening: about 5.5 ms on the PC card, roughly a 10% increase. Leadbetter put the Series X sharpening cost at about 4%, based on figures he had seen.
- Lite model, 4K: 3.11 ms on the RX 6700 XT against 2.75 ms on Series X.
Caveats before you repeat "Xbox beats PC"
- Scaling mode is unconfirmed. Microsoft's table doesn't say which mode produced the 3.86 ms figure. Leadbetter thought it was probably Balanced but said it could be Quality. NoobFeed states Balanced as fact, which overstates what the evidence shows. In the sample's scaling table, a 4K target in Balanced mode renders at 2258 × 1270, so the "about 1270p" figure is only right if Balanced is the mode.
- The test isn't like-for-like. The console figures come from Microsoft and the PC figures from Digital Foundry. The Xbox DLL can't run on a PC, and the two GPUs differ architecturally. The RX 6700 XT is a close comparison point, not an identical chip.
- V-sync can skew PC readings. Digital Foundry notes the sample's v-sync setting can affect GPU clocks unless it is disabled.
- The "why" is partly inference. NoobFeed credits console-specific optimization, INT8 hardware support and memory bandwidth. Those are plausible, but Microsoft's sample and the Digital Foundry material don't prove a single cause. The spec figures NoobFeed quotes (compute units, clocks, TFLOPS, bandwidth) should be checked against official sources before you rely on them. I did not verify them here.
What FSR 4 is doing on non-RDNA 4 hardware
Microsoft describes FSR 4 as machine-learning upscaling. It uses temporal and spatial data from multiple frames to reconstruct a higher-resolution image from a lower-resolution, jittered input. The Xbox sample runs the INT8 model variants. The sample's limitations section says FSR 4 needs a GPU with typed UAV load and R16G16B16A16_UNORM support. It also says the technology is ML-based and requires supported hardware.
That fits the history. FSR 4 launched on Radeon RX 9000 cards in 2025. AMD later brought 4.1 to RX 7000 in June 2026 and to RX 6000 with Adrenalin 26.10.1. AMD says it optimized the INT8 model originally built for RX 7000 to enable the older RX 6000 cards.
It would be wrong to read the sample as proof that Xbox has dedicated AI accelerators. The sources support the INT8 model and the timings, not that claim.
Memory footprint
Microsoft reports 304.03 MB (318,799,872 bytes) of FSR4 memory use on Xbox. That is at a 3840 × 2160 target and 2560 × 1440 render resolution (Quality), excluding swapchain overhead. Full and Lite use the same amount, because memory is driven by resolution-sized intermediate resources, not the model. Leadbetter separately saw PC readings of roughly 318 MB at 4K and 81 MB at 1080p, and said FSR 3 costs a similar amount. His numbers are his own observations and shouldn't be merged with Microsoft's table.
Frame budgets and what developers might do
A 30 fps frame is about 33 ms and a 60 fps frame about 16.7 ms. Leadbetter sees Series X's 1440p costs (1.29 ms Lite, 1.95 ms Full) as potentially better suited to 60 fps modes. The 4K costs may fit more naturally into 30 fps budgets. That is his development-oriented reading, not a Microsoft guarantee, and real games spend the rest of the frame on everything else.
Series S is a harder sell. Its 1080p costs of 1.9 ms (Lite) and 2.9 ms (Full) take a larger share of a smaller GPU. Leadbetter argued ML upscaling could still pay off visually at very low internal resolutions. Digital Foundry also said FSR4 Lite looks about 30% faster than the full model, which matches the Series X pattern in Microsoft's table.
GTA 6: keep it in the speculation bin
NoobFeed ties the story to GTA 6. A November 11 Windows Central report, relayed through the research notes, says dataminers found amd_fidelityfx_loader_xbox.dll and amd_fidelityfx_upscaler_xbox.dll in the Xbox preload. Those files don't confirm FSR 4.1 in the game, and Rockstar hasn't announced such support. NoobFeed notes the files also support FSR 3. Any claim about a GTA 6 frame-rate or sharpness outcome is speculation.
Why Windows and PC readers should care
- RX 6000 owners already have FSR 4.1 through the October driver release. The Xbox timings are a useful reference for how heavy the INT8 model is on RDNA 2-class hardware.
- Developers can build the sample for both Xbox and Windows from one solution. It is a practical way to compare FSR4 Full, Lite and FSR3 on Xbox using the same scene.
- Console players shouldn't expect an instant improvement. Games need to integrate the upscaler, and no retail title has been confirmed.
Bottom line
The documented result is solid: Microsoft's Series X upscaler pass is faster than Digital Foundry's RX 6700 XT readings in this sample. The explanation is plausible but not proven. It will matter once real games ship FSR 4 on Xbox.
Correction (November 13, 2026): An earlier version said AMD brought FSR Upscaling 4.1 to RX 7000-series cards in July 2026. AMD's Adrenalin Edition 26.6.2 release notes, dated June 22, 2026, list FSR Upscaling 4.1 support for RX 7000-series cards, so the feature arrived in June, not July.