The primary goal for PGXP optimization is Vertex Precision and Texture Mapping Accuracy. DuckStation’s PGXP implementation works by intercepting the coordinates sent to the GPU and recalculating them with high-precision floating-point math. This configuration focuses on enabling PGXP Vertex Cache, forcing Perspective Correct Textures, and adjusting the CPU Overclock to handle the extra mathematical overhead without introducing “shaking” artifacts.
Hardware Compatibility & Expectations
- GPU Requirements: PGXP is processed primarily by the CPU, but the final result is rendered by the GPU. Any modern dedicated GPU (or even Intel Iris Xe) can handle PGXP at 4K.
- CPU Single-Threaded Load: PGXP increases the load on the “Geometry Transformation” phase. A CPU with decent single-core speed is required to maintain 60 FPS in heavy titles like Tekken 3.
- Game Compatibility: While PGXP works for most 3D games, it can break 2D elements or HUDs in certain titles. Use “Game Properties” to disable PGXP for 2D-heavy games like Castlevania: SOTN.
File Location
DuckStation uses a unified settings file for the global configuration. You can find it here:
%USERPROFILE%\Documents\DuckStation\settings.ini (Note: If you are using the “Preview” or “Portable” version, the file will be in the settings subfolder within the application directory.)
Technical Configuration (Code Block)
Open the settings.ini file and look for the [PGXP] and [Graphics] sections. To achieve maximum stability, apply the following parameters:
[Graphics]
Renderer = Vulkan ; Vulkan is the most stable for PGXP
ResolutionScale = 5 ; 5x = 1080p/1440p (Sweet spot for PGXP)
TextureFiltering = 1 ; 1 = Bilinear (Removes pixel grain)
AnisotropicFiltering = 16
[PGXP]
Enabled = true
Precision = true ; Enables 32-bit vertex precision
VertexCache = true ; Reduces jitter by caching vertex positions
PerspectiveCorrect = true ; Mandatory to stop textures from "warping"
TextureCorrection = true ; Cleans up edge bleeding between textures
CPUToGPUThreshold = 1.0 ; Balance between accuracy and speedStrategy for PGXP Texture Correction
To make your PS1 games look like native PC ports:
- Perspective Correct Textures: This is the “Magic Fix.” On a real PS1, textures are mapped using affine transformations, which ignore depth. By enabling
PerspectiveCorrect, DuckStation forces the textures to align perfectly with 3D space, removing the “swimming” effect on floors and walls. - The Vertex Cache Advantage: Setting
VertexCache = trueprevents polygons from “snapping” to the nearest integer coordinate. This is what stops Kratos or Lara Croft from looking like they are constantly shivering when they stand still. - CPU Overclocking (Optional): Some games calculate physics and geometry in the same loop. If you experience “slowdown” after enabling PGXP, go to Console Settings and set the CPU Execution Speed to 150%. This provides the extra “cycles” needed to handle the precision math without dropping frames.
Key Performance Parameters
| Parameter | Recommended Value | Impact |
| PGXP Enabled | true | Activates the precision geometry engine. |
| PerspectiveCorrect | true | Stops textures from warping/swimming on surfaces. |
| VertexCache | true | Eliminates “jittery” or “shaking” 3D models. |
| Resolution Scale | 5x | The resolution at which PGXP stability is most visible. |
Frequently Asked Questions (FAQ)
Why do I see “gaps” in the 3D models now?
This is called “Polygon Seaming.” Some PS1 developers relied on the hardware’s low precision to hide gaps between models. When you use PGXP, those gaps become visible. You can try setting “Texture Correction” to false or lowering the resolution scale to hide these seams.
Does PGXP work with 2D games?
No. PGXP only affects 3D vertices. In a game like Final Fantasy VII, PGXP will stabilize the character models but will have no effect on the pre-rendered 2D backgrounds.
Some games use 3D coordinates to draw 2D menus. If the HUD is flickering, try setting the “CPU to GPU Threshold” higher or disable “Precision” in the PGXP menu for that specific game.
Can I use this on the Android version?
Yes. DuckStation on Android supports PGXP, but it is much more demanding on mobile processors. Start with “Vertex Cache” and “Perspective Correct” only, and avoid high resolution scales.
Conclusion and Expected Results
By manually refining your settings.ini to prioritize PGXP precision and perspective-correct mapping, you are removing the technical limitations of 1994 hardware. You can expect rock-solid 3D environments, textures that stay pinned to their surfaces, and a visual experience that looks more like an early Dreamcast or PC title than a standard PS1 game.