Is your CPU the only thing you changed?
So the level in Cubase looks plenty hot in the 2bus/stereo out meters, but is low on your interface/mixer?
Does the MW10c have any kind of control panel?
Have you verified that you are still using ASIO4All within Cubase? Sometimes the driver will become unloaded but Cubase won't really let you know. Going to Devices and selecting the driver again often fixes this sort of thing.