Few weeks back, I finally got my most powerful gaming PC that I have ever used. I installed all the components myself [as usual]. In the city where I live: finding, even an Nvidia 8800 GT is quite impossible: shopkeepers do not have any latest or good 3D card. This is the reason why I got my PC from another country [UK].
Anyway, I got all the components but not the casing. I got the casing from local market but unfortunately, my 3D card [Nvidia 260 GTX] did not fit in it. This was the largest casing [tower] that I could find in the market: so I had to make amendments in the casing [involved cutting : ) ] in order to properly fit the 3D card.
I had to do this as I had no other choice.
Here are the dimensions of my casing without the amendments:
Height = around 15.5 inches
Width = around 7 inches
Length = around 15 inches
If I look at the right side of the casing: there is some space dedicated for the hard drive and other stuff. Now after installing the motherboard, the maximum size [length] of 3d card that I could install was around 9 inches.
And now here are the dimensions [size] of Nvidia GTX 260:
Length = around 10.5 inches
Height = around 1.5 inches
[Please note that: I am considering the height of the card when it is installed. That is: the Thickness of the card]
Width = around 4 inches
[Please note that: I am considering the width of the card which you hold vertically in your hand and that you see the logo on it. The space where you see the logo [vertically] is what I am calling as width]
My casing space for the 3D card was around 1.5 inches short. So that is why, I was not able to install GTX 260 without cutting and making extra space for it.
Anyway, if you are buying this card or any other card in 200 series, then you should see its dimensions and then compare them with your current casing to see if the card will fit in it or not. It is possible that you will have to buy another bigger casing.
