Recently upgraded a 16.04 Ubuntu guest (Windows 10 host) to to 18.04 and saw a massive drop in performance. The lag in the desktop environment was unbearable. This was even with the guest additions properly installed. These settings finally fixed it: SystemMotherboardChipset: ICH9Extended Features: Enable I/O APIC, Hardware Clock in UTC Time.ProcessorExtended Features: Enable PAE/NXAccelerationParavirtualization […]