The SRDx for Photoshop plug-in software wants to make use of Photoshop's performance option to use the power of the GPU for faster image rendering.
On both platforms, macOS and Windows, you therefore want to make sure that this option (enable GPU, and the sub-setting to it: enable OpenCL support) is activated.
On macOS, you do not need to do more than that.
On Windows, you might want to update your graphics cards drivers if it doesn't work out-of-the-box.
The "Update driver" option of the Windows device manager does not suffice here. (Though the device manager may help you to identify the GPU used in your computer.)
If there is an option during installation for a "clean install" or to "use existing settings", go for the clean version without using former preferences.
You can find downloads for current AMD Radeon drivers on:
The Intel Driver & Support Assistant is here:
NVIDIA has its driver download page at:
Especially for Nvidia GPUs, you want to make sure if the drivers support OpenCL v.1.2 or higher for your given graphics card.
The to-date (2025-01-28) latest WHQL GameReady driver (v.566.36) support a wide range of Nvida GPUs, cf. p. 29 ff in: