When do you need fast video cards?

I have been building computers for almost 20 years.  Because of this experience, people have been asking me about what video cards they should get.  Video cards tend to be the single most expensive component in a computer and there is a very competitive market for then.  I tend to tell them to get the cheapest video card they can find and they never listen to me.  They always get the most expensive video card in the range they want to spend.

Why do I tell them to get a cheaper card?  Mostly because I know they don't use any 3D tools that use the functionality of the card.  3D?  What does 3D have to do with a video card?  A little history.  You used to have two cards in your system for video.  One was your standard VGA card.  The other was a 3D accelerator card.  The 3D accelerator cards exposed a 3D API that programmers could use to make 3D applications faster.  These 3D cards had special chips (GPU) that performed very fast 3D operations.  At the time, the only applications that used the 3D API were high end games and high end graphic workstations.

Over time, the companies that made the 3D accelerator cards decided to merge the 2D VGA card with the 3D accelerator card.  Since every 2D card is almost the same, the manufacturers marked the 3D features.  A 3D arms race ensued and the 3D parts of the cards got better and faster and contained more features.  For many years, there were still only two types of applications that used those fancy (and expensive) features: 3D games and high end graphic workstations.

This is where myth #1 was used by people who wanted high end graphics cards.  They heard that the 3D features were used by high end graphics workstations.  They didn't know what high end meant, but nothing is higher end than Adobe Photoshop, right?  Wrong.  Photoshop deals with a particular branch of graphics.  Specifically, manipulation of 2D raster images.  People are the most familiar with Photoshop because to a non-technical person, manipulating a 2D raster image is what graphics is.  In the history section, we learned that the expensive part of the video card is for doing 3D, though.  What is a high end graphics program that uses 3D?  RenderMan.  For those of you not familiar with RenderMan, it is the high end graphics program written by Pixar to render all the Pixar movies, Titanic, Lord of the Rings, the Star Wars prequels, and most major movies with awesome special effects.  RenderMan allows you to view a lower resolution frame of the movie in 3D in real time.  The graphic artist can manipulate the 3D scene for the movie.  RenderMan then renders the full scene in a much higher resolution.

As time went on, people started realizing that the GPU was far better at some math than a typical CPU.  GPU manufacturers added a new API so that programmers could start using the GPU for things other than real time 3D rendering.  People started using the GPU for massive public projects, like decoding the human genome or searching for extra terrestrial life.  Some used it to accelerate delayed 3D rendering.  Enter myth #2: I do video editing, so I need a fast GPU.  This stems from the fact that programs like RenderMan started using the GPU for the rendering part of the movie creation.  Once again, they are doing 3D movies.  Home videos are not rendered, they are captured.  Although video programs like Adobe Premier do allow you to use the GPU to speed up the encoding/compression phase of making your video, it is not worth the money unless you are making movies professionally.  If you make one movie a month, save the money.

Unless you are playing cutting edge video games, the main thing to consider is resolution.  Modern operating systems run in 3D mode to give you fancy eye candy.  This means if you want a high resolution, you need a decent video card with enough DRAM to handle the resolution.  The faster your card, the smoother your eye candy will be.  For video games, base your selection on the specific video game that you want to play.  Most of the 3D games I play are over 5 years old.