In short this means that different types of cards from different manufacturers and different calss of cards can be used flawlessly. For those that are confused; some edumication:
Right now there are two two companies who make the chips and design the ICB (integrated circuit board). NVIDIA and ATI.
NVIDIA makes the GForce and ATI make the Radeon. Which one is better is a long debate. To get better graphics you need a better video card OR you can take and place multiple video cards together. The problem lies in the rules for using multiple video cards. There can be issues, including drivers and in the case of NVIDIA, you must have two identical video cards.
What this means:
This allow for the following things:
1. It can allow for high end cards to be placed together to make extreme end graphics.
2. It can allow for multiple displays to be run independently thus offloading CPU stress.
3. It can allow for multiple cheap cards to be combined into one decent card, or to take advantage of what each card does well.
4. It can allow to keep and use your older video card, while still upgrading into something new but less expensive.
Who cares about this?
Well pretty much everyone. This could dramatically increase the graphics capabilities of a console without significantly increasing cost, and allows for those working on extreme high end CAD systems to gain more juice for business. It's also a PC gamers upgrading dream, by always being able to use all the cards they own to get better graphics, it allows for much better, targeted, and cost effective scalability.
And that might just be news to you.
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