After removing the rather dinky stock ATI
fan-heatsink, we cleaned the R300 core of all the residual yellow thermal interface
pad and applied a small amount of the white silicon thermal compound Zalman include in
ATI's stock cooler as you are probably already
aware, offers sufficient cooling by way of a thermal interface pad,
but doesn't actually make direct contact with the silicon core.
The shim around the edge of the processor package is just slightly higher
than that of the core so a flat base on any heatsink will cause the
The original ZM80-HP mounting base was
designed with a flat bottom, but with the revisions and other
improvements Zalman have made to the ZM80A-HP this problem has been addressed. While
the ZM80-HP could be used with a Radeon 9700, I'd really only
recommend using the updated ZM80A-HP model we are testing here.
The machining around the outside of the of the
extruded base is very shallow, not more than maybe 0.003", but offers
sufficient clearance for it to contact the R300 core. We tested this
out with very small amounts of silicon to see where the imprint landed,
and the silicon did indeed make contact with the aluminum.
Some Radeon's (or for that matter nVidia-based cards) will come
with pre applied BGA ramsinks which can
be difficult to remove. Since the base is 15mm thick you
have at least that amount of space to work with on the rest of the
card. Any ramsinks falling under the Zalman heatsink have to
be smaller than 15mm tall or the assembly will not sit