ASUS' new GeForce GTX 580 DC2 uses a massive triple slot Direct CU II heatsink that increases cooling performance significantly. As a result the card is extremely quiet in both idle and load - quieter than many midrange cards. ASUS has also increased the operating clocks of their design, all this for a small price increase of $5.
Any major computer upgrade generally requires a full software reinstall too. No so if you heed the advice in the guide to Upgrading a Motherboard without Reinstalling. PCSTATS Tips