Below is a list of features supported and unsupported in this phase one release of XPU

General

DCCS

Shading

BxDFs, Displacements, & PatternsRISXPUNotes

PxrSurface

Some Subsurface modes are not available.
Certain single scattering scenarios are not supported.

Second refraction roughness is not yet implemented.

PxrLayerSurface


PxrDisneyBsdf


PxrMarschnerHair


PxrConstant


PxrDiffuse
PxrDisplace

MaterialX Lama


PxrVolume, Volumes


OSL Patterns

PxrDirt & PxrCurvature not supported

C++ Patterns



PxrSeExpr

Baking



Point Clouds




Patterns & Textures

OSL




Lighting


LightsRISXPUNotes

Analytic Lights

PxrEnvDaylight, PxrCylinderLight not available; some light parameters not available
Dome LightsDome lights are always visible in refractions
Light Portals

Mesh Lights


Light Filters



Light Linking



Scalability to many lights





As the light selection scheme in this phase one release of XPU is yet to be implemented, we recommend keeping the number of lights in your scene to a minimum.




Geometry


GeometryRISXPUNotes

Subdivision Surfaces

Catmull-Clark only. No support for hierarchical subdivision surfaces.

Polygonal Surfaces



Nurbs



Curves


Points

Falloff is not supported
Quadrics and Blobbies
Procedurals
Nested Instancing Varying attributes to drive differences in materials per-instance is not yet supported.
Only 4 levels of nested instancing are supported.
Watertight dicing of subdivision surfacesXPU cannot opt out of watertight dicing.
Watertight dicing of displaced polygonal surfacesXPU cannot opt out of watertight dicing.
Nested dielectricsXPU does not support intersectpriority or nested IOR tracking; refractions may be wrong when leaving an inner nested dielectric material
Dicing cameras





Integrators


Integration & Ray TracingRISXPUNotes

PxrPathTracer

Some features not available

PxrUnified


PxrVCM


PxrOcclusion 

PxrVisualizer

Some features not available
PxrDefault





Rendering


Post ProcessingRISXPUNotes

Sample and Display Filters



PipelineRISXPUNotes

AOVs and LPEs



EXR, TIFF



Deep Output



Matte, Holdouts



PxrCamera
Crop windowsXPU support will be available in 24.2. crop windows in 'it' will be available in 24.4. 
Advanced DOF controls (bokeh, etc)