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A Gaming enthusiasts may recognise the acronym SLI, which stands for Scan Line Interleaving. To take advantage of SLI, you need two 3D pass-through adapters, linked by an internal cable. One card draws even-numbered scan lines on your screen, while the other handles the odd numbers. By sharing the burden of image generation in this way, it's theoretically possible to double video performance. Pair up a couple of Diamond Monster 3D II cards, for example, and you will have a system that can spit out 100 frames per second.

But such blistering speed comes at a cost. You can't mix and match old 3D cards with newer ones. To use SLI, you need two cards from the same manufacturer, and they have to be identical models with identical memory configurations.