We're just trying to prepare ya for the things adding a fire-breathing dragon for a 3d card can instigate. 
They draw more power, and as a result, they produce more heat. Tight, cramped cases with a poor, low-end power supply and inadequate case cooling can have problems, instability or poor performance. It's important to go into the deal realizing you may have problems.
It can often times be like trying to bolt a Ferrai V12 into a VW Bug chassis. Obviously if your PC is more like a Jetta than a Bug, you'll have better results.
They draw more power, and as a result, they produce more heat. Tight, cramped cases with a poor, low-end power supply and inadequate case cooling can have problems, instability or poor performance. It's important to go into the deal realizing you may have problems.
It can often times be like trying to bolt a Ferrai V12 into a VW Bug chassis. Obviously if your PC is more like a Jetta than a Bug, you'll have better results.