The Kanie
Hedgehog 238M is a CPU cooler for people who reckon that Alphas just aren't
extreme enough.
My Hedgehog came from Overclocker's
Paradisehere in Malaysia , who have as I write this sold out of them, but more
will presumably be on the way soon. The 238M's $RM 195.00 , which is not
very much more expensive than a similar-shaped Alpha , especially if you
have to buy that Alpha from overseas.
The Hedgehog's basic design
is very Alpha-esque - lots of tall pins, shroud, big fan sucking air through
the heat sink - but that heat sink's not made of aluminium. It's made of
copper.
The aluminium used for almost
all PC heat sinks (usually some flavour of 6063 alloy, for the metalworkers
out there) is strong, light, not terribly expensive and has good thermal
and electrical conductivity.
But aluminium only has about
half the thermal conductivity of copper, which is about as good a thermal
conductor as silver. Higher thermal conductivity lets heat get from the
CPU contact patch to the whole pin surface area more easily; the better
your thermal conductivity, the better your heat sink cools the CPU.
So why aren't all heat sinks made
of copper? Well, copper's structurally lousy - either very soft, or too
brittle to be used for heat sink pins, depending on how it's treated. The
Hedgehog's made of soft copper, and comes with a stern warning about not
grabbing its heat sink by the pins, lest you bend them.
Copper's also very heavy. Make the
exact same heat sink out of copper instead of aluminium and it'll weigh
about 3.3 times as much. The Hedgehog 238M weighs a hefty 445 grams all
told. That's almost a pound!
The weight of the thing makes
it a dodgy proposition if you're installing it on a CPU in a "slotket" adapter
card, to let you use Socket 370 processors on older Slot 1 motherboards.
That much overhanging weight puts a lot of strain on the CPU mounts, which
in many slotkets are pretty slapdash affairs.
Not that many people don't install
Gargantuan hunks of metal on their Slot 1 or Slot A CPUs - Alpha's P7125M60 for Slot
A Athlons and old-model "SECC" Intel CPUs is an aluminium monster that weighs
more than the Hedgehog. But it mounts on a full processor cartridge, not
a flimsy socket.
Like the Alpha coolers, the
Hedgehog comes as a kit. And, like the Alpha kits, this one's very easy
to put together. It comes with the same sort of clip as the Alphas, too,
which makes it simple to install once you've built it.
The Hedgehog comes with a high-output
Y.S. Tech fan, which shifts about 50% more air than the Sanyo Denki fans
that come with the larger Alphas.
The Hedgehog heat sink comes shrink-wrapped,
to keep it shiny and un-corroded. Corrosion on the pins shouldn't make much
difference to anything, but a layer of oxide on the bottom of the sink would
impede heat transfer.
Pretty, ain't it?
The Hedgehog has a plain flat base
plate, with a rebate for the end of the Zero Insertion Force socket that
contains the cam-activated CPU locking mechanism. This means I'd be a bit
nervous about using a Hedgehog with an FC-PGA CPU, especially if the motherboard
was going to end up mounted vertically, rather than horizontally. All of
that weight bearing down on one edge of the CPU core could do it a mischief.
Fortunately, there's something you
can do about this problem. Shim your CPU. A square of metal just the right
size between CPU and cooler, with cutouts for the CPU core and any other
top-of-chip components, takes the strain off the core. And Cool PC also
sell shims for FC-PGA and Socket A CPUs.
Socket A CPUs are much more fragile
than Socket 370 ones. The top of the CPU, on which the cooler sits, has
similar physical properties to a little bit of glass. Get your cooler installation
wrong, and it's easy to bust off a corner of the top of the CPU.
This seldom actually kills the chip,
but it's disturbing, especially if you fail to clean up the fragments properly
and grind little bits of glass between the cooler and the CPU on your next
mounting attempt.
The four little rubber dots
stuck to the top of the Socket A CPU package aim to reduce this problem;
they stop you from getting your cooler too far off level. But they're not
perfect.
This Japanese-made copper shim aims
to solve the problem, by giving the cooler a much larger contact area.
The hole in the middle is for the
CPU core; the slots around it are for the little surface mount components
on the top of the chip package.
