Expansion slots are generally referred to as PCI and PCle slots via which you can add an additional RAID card (if your chipset has supportfor it), graphics card, audio Card, LAN card, etc. So, it's important to have more onboard slots, so that your motherboard has more expansion options.



We have seen motherboards with just single PCI and PCle slots, and they are decent enough when it comes to entry-level boards, but for high-end motherboards you'll surely need more than that.

For SLI and CrossFire to work you need at least two PC Ie slots. So, if expandability is there on your mind, opt for a motherboard that has maximum expandability options.