There is a memory leak in the OpenVR SDK that affects OBS if the plugin is active but SteamVR is not running.

Source code is available here: https://github.com/baffler/OBS-OpenVR-Input-Plugin

This plugin provides an input plugin to 64bit OBS that allows capturing directly from OpenVR/SteamVR mirror surface in full resolution.Either left or right eye image can be captured.Cropping can be configured in the plugin properties, with some presets provided for the HTC Vive. The presets take into account the OpenVR mask to provide a maximum capture area without any black borders. However some OpenVR games still render to these mask areas so with those games cropping is not necessary.To use extract the zip file to your OBS directory and a new "OpenVR Capture" source should appear in the sources list.You may need to install the Visual Studio 2015 x64 runtime if you do not already have it installed, it can be downloaded from here This state causes the plugin to slowly leak memory as it tries to periodically initialize OpenVR. This is unfortunately a "feature" of the OpenVR SDK.