Indeed, SLI requires both cards with SLI capability, as well as a motherboard that supports SLi. That means you need a motherboard that has two PCI Express slots spaced far enough apart to accommodate the SLi dongle, which comes with the motherboard (not the cards). If the card that you currently have doesn’t have SLi capabilities, that means you’ll have to buy two SLi cards, even if you have a motherboard that already supports it. But unless you’re planning to run video games at super high resolutions with anti-aliasing turned on, I wouldn’t worry about SLi at all anyhow, as it provides no real benefit to everyday computing.