i don't have performance tab in preference options
What was mentioned in a Lr6 feature..
What is your OS and computer specs???
no external hard drive, spyder 3 pro and wacom is connected.
all drivers all up to date, fresh windows, only photoshop, lr5, bridge and kaspersky is installed on this machine
Please disconnect Spyder pro and Wacom and then restart Lightroom and check its performance.