MSI 990FXA User Guide - Page 36

Hardware Setup Slots PCIE (Peripheral Component Interconnect Express) Slot The PCIE slot supports the PCIE interface expansion card. PCIE x16 Slot PCIE x1 Slot PCI (Peripheral Component Interconnect) Slot The PCI slot supports LAN card, SCSI card, USB card, and other add-on cards that comply with PCI specifications. 32-bit PCI Slot Important When adding or removing expansion cards, make sure that you unplug the power supply first. Meanwhile, read the documentation for the expansion card to configure any necessary hardware or software settings for the expansion card, such as jumpers, switches or BIOS configuration. PCI Interrupt Request Routing The IRQ, acronym of interrupt request line and pronounced I-R-Q, are hardware lines over which devices can send interrupt signals to the microprocessor. The PCI IRQ pins are typically connected to the PCI bus pins as follows: PCI Slot1 Order1 Order2 Order3 Order4 INT E# INT F# INT G# INT H# 2-20