Many users have rightfully complained that BlueStacks runs slow when their PC is also running the Avast antivirus. Avast slows down BlueStacks due to one of its settings. Please update your Avast antivirus settings as described below
1. Go to 'Settings' of Avast-Antivirus as shown below.
2. Click on 'Troubleshooting' on the left-hand side, uncheck the 'Enable hardware assisted virtualization' option then click on 'OK' to confirm and reboot your PC. You should experience BlueStacks feeling a lot more zippy after this.
If you have any further questions, please send email to support at bluestacks dot com.