I have read that while the underlying chips are essentially the same, the design of the board is different.
Gamers want performance, and tend to favor overclocking and other things to get high frame rates but which maybe burn out the hardware occasionally.
Businesses want reliability, and tend to favor underclocking so they can be sure that their people can keep working.
Also, I have read that the quadro boards use ECC memory.
If you don't know what ECC memory is about: it's a [relatively] well known fact that sometimes memory "flips bits (experiences errors)". This does not happen too often, but is an unavoidable consequence of the underlying physics of the memory cards and the world we live in. ECC memory adds a small percentage to the cost and a small penalty to the performance and has enough redundancy to correct occasional errors and to detect (but not correct) somewhat rarer errors. Gamers don't care about that kind of accuracy because for gamers those are just very rare visual glitches. Companies do care about that kind of accuracy because those glitches would wind up as glitches in their products or else would require more double or triple checking (which winds up being a 2x or 3x performance penalty for some part of their business).
Another issue I have read about has to do with hooking up the graphics card to third party hardware. In other words: sending the images to another card or to another machine instead of to the screen. Most gamers are just using canned software that doesn't have any use for such capabilities. Companies that use that kind of thing get orders of magnitude performance gains from the more direct connections.
