Upscaling 101 (FSR/DLSS/XeSS)
More FPS by drawing fewer pixels—without tanking image quality.
Audience: university-level gamers/builders
Goal: explain how modern upscalers work—FSR (FidelityFX Super Resolution) from AMD, DLSS (Deep Learning Super Sampling) from NVIDIA, and XeSS (Xe Super Sampling) from Intel—so you can use them confidently, measure the gains, and spot artifacts.
The one-paragraph idea
Most games spend the majority of time rendering the 3D scene. Upscaling renders that scene at a lower internal resolution, then reconstructs it up to your screen’s resolution. Done well, you keep much of the sharpness while gaining a lot of performance (often the difference between “nearly smooth” and “buttery”). Upscalers differ in how they reconstruct: some use the current frame only (spatial), others use temporal history and motion vectors (data about how pixels move) for higher quality.
Quick map of the players
FSR (FidelityFX Super Resolution) — AMD’s solution.
FSR 1: spatial upscaler (fast, simpler).
FSR 2/3: temporal reconstruction (better detail/stability than FSR 1).
DLSS (Deep Learning Super Sampling) — NVIDIA’s AI/temporal upscaler; requires RTX hardware for its neural models.
XeSS (Xe Super Sampling) — Intel’s AI/temporal upscaler; best on Intel Arc, also runs on other GPUs via a general compute path.
(All three are enabled per game in the graphics settings. Driver-level options also exist—see “Driver upscalers” below.)
Spatial vs temporal upscaling (and why it matters)
Spatial upscaling
Uses only the current frame.
Pros: very fast; works in almost any scene.
Cons: less information → edges can look softer, more shimmering in motion.
Temporal upscaling (FSR 2/3, DLSS SR, XeSS)
Uses current + previous frames plus motion vectors from the game engine.
Pros: better detail retention, fewer jaggies, improved stability on thin geometry (fences, foliage).
Cons: needs good integration and correct motion vectors; can show ghosting (trails) if vectors/transparency masks are off.
Key terms (expanded once)
Motion vectors: per-pixel hints the engine provides about where things moved between frames. Upscalers use them to reproject detail.
Reconstruction quality: how “native-like” the upscaled image looks, especially on moving edges, foliage, and sub-pixel detail (wires, hair).
Ghosting: faint trails behind moving objects—often from incorrect motion vectors or aggressive temporal accumulation.
Shimmer: tiny flicker on thin, high-contrast details (fences, power lines), usually visible during camera pans.
UI scaling: whether the user interface (HUD, text, crosshair) is drawn at native resolution (best) or gets scaled with the 3D scene (can look soft).
Choosing a mode (Quality/Balanced/Performance)
Most games expose three or four upscaler modes:
Quality: highest internal resolution → best image, solid FPS boost.
Balanced: middle ground.
Performance / Ultra Performance: lowest internal resolution → biggest FPS jump, most visible artifacts.
Practical starting points
4K displays: try Quality first; drop to Balanced only if needed.
1440p: Quality is the sweet spot for most GPUs; Balanced if you’re still GPU-bound.
1080p: upscaling has the least headroom; prefer native or a Quality mode only if you really need the frames.
Driver upscalers (when the game doesn’t have one)
AMD RSR (Radeon Super Resolution): driver-level upscaling that works for almost any game; toggled in AMD Software: Adrenalin Edition.
NVIDIA NIS (NVIDIA Image Scaling): driver-level spatial upscaler/sharpening.
Intel currently focuses on in-game XeSS.
Trade-offs: Driver upscalers don’t see engine motion vectors, so quality is closer to spatial methods and the UI/HUD may get scaled (softer text) unless the game draws UI at native.
How to evaluate image quality (what to look for)
Open a scene with a mix of thin detail, textured surfaces, moving objects, and UI text.
Edges & foliage: look for shimmer during a slow pan.
Moving objects: watch for ghost trails behind characters or vehicles.
Transparency (smoke/fire): check for weird halos or blotchy patterns.
UI/HUD: is text crisp? If it’s soft, the game may be scaling UI with the scene—look for a “Render UI at Native” or “Separate UI scaling” toggle.
Sharpening sliders: avoid double sharpening (in-game + driver). Use one, at modest strength.
Hands-on lab (15 minutes, vendor-neutral)
Tools: a game with an upscaler (FSR/DLSS/XeSS), a frame-time logger (CapFrameX/PresentMon/OCAT), and a screenshot tool.
Settings: fix resolution (e.g., 2560×1440), preset (High), API (DirectX 12/Vulkan), and display mode (exclusive fullscreen).
Baseline (Native): run the same 30–60s scene 3×. Log Average FPS + p95 frame time + 1% low FPS. Take a screenshot.
Quality mode: enable FSR/DLSS/XeSS – Quality. Run 3×; log and screenshot the same frame.
Balanced mode: repeat.
Compare:
Build a small chart: FPS vs perceived sharpness (your notes).
Inspect screenshots side-by-side (NVIDIA ICAT is great) at 100% zoom and during motion.
Pick the lowest mode that still looks “native-like” to you.
Tuning tips (by symptom)
Shimmer on fences/foliage: prefer Quality mode; reduce sharpening a touch; ensure TAA (Temporal Anti-Aliasing) is on if the game expects it.
Ghosting trails: try Quality; if the game offers an “anti-ghosting” or “reactive mask” option, enable it. Some titles simply need patches—use the better-behaved mode meanwhile.
Soft UI text: look for “native UI” or “separate UI scale” toggles; if none, consider driver upscalers off and use the in-game one instead (most in-game upscalers keep UI native).
Too much grain/over-sharpen: lower the sharpening slider or disable extra film grain; avoid stacking driver and in-game sharpening.
When upscaling shines (and when it doesn’t)
Great fits
High-resolution play (1440p/4K) on mid-range GPUs.
Ray-tracing workloads where native is too heavy.
Laptop thermals/noise: render fewer pixels → less heat.
Use with care
1080p on a fast GPU (little benefit; artifacts are more visible).
Titles with known ghosting until patched.
Competitive shooters where you want the absolute cleanest motion edges—test carefully and prefer Quality mode.
FAQs
Does DLSS “look better” than FSR/XeSS?
It depends on the game’s integration, your GPU, mode, and scene. Temporal upscalers generally look better than spatial; among temporals, quality varies title-to-title. Test your game.
Should I enable sharpening?
Yes, but moderately. Start with the in-game sharpening slider at a low value. Avoid double-sharpening (don’t stack driver + in-game).
Can I combine upscaling with frame generation?
Often, yes (many games pair them). Remember that frame generation adds latency—great for single-player smoothness, not ideal for twitch shooters. (We’ll cover frame-gen deeply in the next blog.)
Cheat-sheet: default recommendations
4K: Upscaler Quality → Balanced only if needed.
1440p: Quality first; Balanced if GPU-bound.
1080p: Prefer native or Quality; avoid lower modes.
Always: keep UI at native, pick one sharpening path, and verify with p95 and 1% lows—not just average FPS.
Takeaway: Upscaling is a legit performance tool—not just a band-aid. Use Quality modes first, judge with frame-time p95/1% lows plus a visual check for shimmer and ghosting, and you’ll unlock smoothness that used to demand a bigger GPU.
