What's the difference?

Hardware GPU
1

I found this on Amazon and I just wan't to get the ASUS R9 280X DCUII TOP V2, but I don't know what the difference is between these cards.

http://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Daps&field-keywords=ASUS+R9280X-DC2T-3GD5-V2&rh=i%3Aaps%2Ck%3AASUS+R9280X-DC2T-3GD5-V2

2

They have different coolers and/or clocks, for ASUS you can check it at
http://www.asus.com/Graphics_Cards/AMD_Series_Products/

3

one is a triple slot and one is a dual slot.  I think the dual slot one is better personally

4

Cheers.