However, multi-GPU configurations are not without their problems. First, multi-GPU systems will use more power and pump out more heat. They're also more constrained by their drivers; for graphical performance to scale with the extra power afforded by an SLI or Crossfire setup, Nvidia and AMD must specifically optimize their drivers and include a profile for a particular application or game. Technically, every graphics card is only as good as its drivers, but SLI and CrossFire add another layer of complexity that needs to be addressed to realize any benefits from the additional graphics card or cards. Still, it's relatively easy and worth setting up if you have the space in your case (and room in your budget).
This story, "How to trick out your gaming PC with multiple graphics cards" was originally published by PCWorld.