Gigabyte GA-Z77X-UP5 TH rev. 1.0 User Manual page 47

Channel A/B Timing Settings
This sub-menu provides memory timing settings for each channel of memory. The respective timing setting
DRAM Timing Selectable is set to Quick or Expert. Note: Your system
may become unstable or fail to boot after you make changes on the memory timings. If this occurs, please reset
the board to default values by loading optimized defaults or clearing the CMOS values.
BIOS Setup - 46 -