Asus RAMPAGE IV BLACK EDITION - Manual (Page 116)

3-26 Chapter 3: BIOS setup
Chapter 3
3.6.2 System Agent Configuration
PCIE_X16_1 / PCIE_X16/8_3 and PCIE_X8_4 / PCIE_X8_2 Link Speed [GEN3]
Allows you to select the target link speed.
Configuration options: [Auto] [Gen1] [Gen2] [Gen3]
3.6.3 PCH Configuration
High Precision Timer [Enabled]
Allows you to enable or disable the High Precision Event Timer.
Configuration options: [Disabled] [Enabled]