Form Factor

• As of 2006, PCI-Express has become the primary form factor (i.e., size) for new video cards, replacing AGP. PCI-E is supported by most newer motherboards and should be preferred when upgrading from AGP or PCI. Users with older motherboards may be restricted to older AGP and standard PCI cards, which are not as powerful but considerably cheaper.
  
  

Performance

• NVIDIA cards are released by series (e.g., FX, GS or GTS). As of September 2010, the cards in the GTX series are the fastest NVIDIA video cards available. Within each series, there are cards designed for low-, mid- and high-end computers. Using any number of free 3D benchmarking utilities, you can get specific numbers and information to get a better idea of the power of a particular card.
  
  

Price

• While the architecture of cards in a series remains the same (for the most part), clock speeds and memory interfaces are adjusted, which affects the pricing of the card. A low-end card in a new series will generally cost around $200 (as of September 2010) and will perform well for one to two years before showing its age in more graphically intensive applications such as 3D games. It is not uncommon for the newest, fastest video card in a series to cost $500 or more.