Hi, I dont know, whether is a Blender-Only problem or whether it is introduced by changes made while updateing Gentoo.
The setup is as follows 02:00.0 VGA compatible controller: NVIDIA Corporation GM206 [GeForce GTX 960] (rev a1) 07:00.0 VGA compatible controller: NVIDIA Corporation GF108 [GeForce GT 430] (rev a1) Nvidia-drivers: 390.48 The GT430 is for rendering the desktop only. The GTX960 is fpr GPU based rendering only. This can be configured via Blender by choosing the GTX960 as CUDA-device and by setting CUDA_VISIBLE_DEVICES=0 as environment variable. All this was done before the interactive performance of Blender goes underground. Everything works well with this setup. GPU-Rendering itsself is uneffected, though. I am using the current stable version of Blender 2.79. on Linux-4.15.17 (vanilla). As an example for the current performance drop: Clicking a checkbox in the "User preferences" dialog take up to 5 seconds before getting updated/checked. >From a backup I restored all Blender settings from a time, when everything works fine but with no success. Dmesg does not show any evidence...for my eyes. I am a littled desperate, since modelling is directly influenced by the performance of the 3D_View port. Does anyone have any idea, what's happening here? ny helpful hint is very appreciated! Cheers Meino