&gt; WDDM 2.0 gpummu is supposed to ensure that the memory has been zeroed between different applications that use virtual GPU memory.<p>Which Windows version introduced this WDDM version? Could it be that OP is running an older version?<p>&gt; WebGL was amended to request a zero when provisioning or disposing of a buffer but it relies on the API<p>This is indeed a tricky situation. All modern GPUs do &quot;zero bandwidth clears&quot; which means that upon clearing, nothing gets written to the actual framebuffer, the memory is just marked &quot;cleared&quot; (by writing some special bits to the L2 cache, for example). This makes it difficult to reason whether there&#x27;s any sensitive content left in the framebuffer.<p>edit: nevermind, the OP seems to be using OSX, so it&#x27;s not WDDM. Additionally, the OSX GPU drivers are written by Apple.