Your chipset is usually covered with a trailing length of heatpipes connected to several ‘node’ heatsinks, combining anything hot into one heat removing clump of metal. While this method works, once you start overclocking, the PWM area’s heat is passed to the Northbridge and vice versa, lowering the potential money-saving extra frequency.
There are stand alone chipset coolers out there, but more often than not, you don’t have the option of using them. Due to the single-piece cooling system motherboards use, you can’t just remove the chipset part as the other sections are left naked. The other problem is compatibility as you have to squeeze the new cooler into a position where it doesn’t conflict with a graphics card or even your CPU cooler.
Today I have the Zaward Twin Towers which hopefully will be able to beat these issues.