Despite the minor version number change, Arnold 7.2.3 represents a significant performance improvement, especially when rendering on a graphics processor or when the user is an owner of Houdini. The new Global Light Sampling (GLS) system introduced in Arnold 7.2.1 is now supported in Arnold GPU. Just like the original CPU implementation, this update is advantageous for scenes with "moderate or high" numbers of light sources, roughly speaking, around 10 or more light sources, rendering "2-6 times faster."
Scenes that did not receive these benefits usually render "a few percent" faster and in some cases, might even render slightly slower.

In addition to the mentioned updates, Arnold for Houdini (HtoA), the plugin for integrating with Houdini, has gained built-in support for Apple Silicon. Notably, Houdini itself started supporting these processors used in modern Mac computers earlier this year. As a result of this change, performance speeds up by "up to 1.45 times," though in the initial version, only the previous-generation M1 Apple processors are supported.
Previously, native Apple Silicon support was only available in Arnold for Cinema and Arnold for Maya.

Among other changes in the Arnold 7.2.3 release, there are new return direction and distance to nearest hit parameters in the distance shader, used to create digital makeup effects in the example above. It's worth noting that the update further expands the support for OpenUSD, primarily when rendering curves.

Currently, three Arnold integration plugins have been updated to support the new features:
Cinema 4D: C4DtoA 4.6.4
Houdini: HtoA 6.2.3.0

Maya: MtoA 5.3.3, along with Arnold 7.2.3, is available for Windows 10 and above, RHEL/CentOS 7 and above Linux, and macOS 10.13 and above. Integrations are available for 3ds Max, Cinema 4D, Houdini, Katana, and Maya.

GPU rendering is supported only on Windows and Linux, and it requires a compatible Nvidia graphics processor. The software is available only through a subscription model, with a cost of $50 per month or $400 per year for a single user.