Taken from
http://www.xsreviews.co.uk/reviews/graphics-cards/sapphire-x1950-pro-agp/3
The other main difference is the PCI-E - AGP chip on the back of the AGP
card. Nvidia have a similar chip on their cards known as the "HSI" or High
Speed Interconnect chip. Both of these allows natively PCI-E cards to be
used in AGP sockets without a redesign of the core. This technology was
first used in reverse (to make native AGP cards work in PCI-E ports) when
PCI-E was first being used so that Nvidia didn't have to change the
architecture of their AGP cards to get the cores to work with the new PCI-E
sockets.
The chip is surrounded by a thermal pad and looks like it should be fitted
with a heatsink. This can easily be done if you have one and some heatpaste
handy; though there are no mounting holes or clips.
Just to add I have put a small chipset heatsink on mine.
TGH
