A couple readers have written to
ask if Frostytech can test the novel copper
foam heatsink used on a new crowd funded silent computer system making the
rounds. Well, we can't because it
doesn't yet exist.
In case you missed it, this is what all the hoopla is
about.... this is the mock-up from SilentPowerPC.de who are looking to raise €45,000.
Copper metal foam structure.
The crowd funding project aims to use a slug
of copper inside the open cell copper metal foam as the heat spreader, with
the metal foam on the outside serving as the "fins" of the heatsink. In
this design, airflow is not fan-driven, but by convective air currents (hot air
rising) so the system remains completely silent. The project touts such benefits
as: "heat is distributed on an up to 500-fold greater surface area."
While open-cell metal foams are routinely used in water blocks and evaporative cooling systems,
I can't see the mockup design successfully working as
a passive CPU heatsink.
For starters, the random cellular structure of metal foam is going to create significant pressure drop which
will styme free airflow. To make matters
worse, the base is entirely blocked off by the heat generating
components and a solid heatspreader... so air can really only enter
the metal foam from the edges. Compare SilentPowerPC.de's thermal
design to the prototype heatsinks actually produced by the
metal foam industry to promote the application of their products (below).
See the difference? Thin slabs of open cell metal foam to
reduce pressure drop and tubing or heatpipes to conduct the heat energy across a
large surface area.... and a requirement for high pressure fans
drive airflow through the restrictive material.
The SilentPowerPC.de team would, perhaps, be better to choose a proven fully
passive heatsink such as Nofan's CR-80EH, which actually exists. NoFan heatsinks
are essentially made from one wound up 'heatpipe', the downside being the volume
of space required and a dissipation ceiling of about 90W. Considering that the
SilentPowerPC.de crowd funding project aims to squeeze an Intel Core i7 4785T CPU
and NVIDIA GTX 760 GPU in the box, I'm skeptical they will build
a working prototype with the metal foam heatsink as