OK, so let's
assume you've decided to buy an Athlon and a board to suit. In Australia
at the moment, the best Athlon motherboard on the shelves is still ASUS'
K7M,
based on AMD's own not too exciting Irongate chipset. Current K7Ms are perfectly
good boards; with the latest BIOS versions (you can get updates from here)
you can activate the "Super Bypass" feature that gives you a bit more RAM
bandwidth, and as long as you have a decent Power Supply Unit (PSU) in your
PC, everything should work fine. Earlier K7Ms were more troublesome, especially
with sub-300W PSUs. You'll only pay about $AUD100 for a 300W PSU, if you
need to upgrade.
You can get a
few other Irongate-based Athlon boards, like FIC's
SD11 and MSI's
K7 Pro, but the K7M's still the best bet, I think, for stability
and support.
The other Athlon
chipset of interest is VIA Technologies' KX133, which is a bit more refined
than the older Irongate and gives a little more performance. The difference
isn't big, though, and KX133 based boards are taking their own sweet time
to arrive here in backwards little Australia. I'm impatient; I grabbed a
K7M.
Keeping
cool
The Athlon prices
I quote above include a CPU cooler perfectly adequate for keeping the Athlon
happy at its rated speed. When CPUs get too hot, they stop working. It's
actually very unlikely that an overheating problem will damage your CPU,
but if your computer crashes every 15 minutes, you may decide to do the
damaging all by yourself.
Athlons need decent CPU coolers,
but they don't need them as much as you might think. They run hot, but they're
meant to.
I have personally witnessed
a perfectly functional but alarmingly hot Athlon, which got that way because
of a defective Peltier cooler. The non-functional "cooler" was pretty much
equal to no heatsink at all - heck, by blocking air flow to the thermal
plate of the Athlon cartridge, it probably insulated the CPU!
That CPU, on a hot summer night,
was far too hot to touch. I've seen hotter computer componentry in machines
whose cooling fans have failed, but I've never seen hotter componentry that
worked. That Athlon did, perfectly, for days on end - and it's still working
today, although it's got a proper cooler on it now!
If you put a better-than-stock
cooler on your Athlon, though, you'll help keep its temperature down, and
keeping the temperature down is essential for overclocking. Overclocking
is running processors faster than they're meant to go. And it's fun.
Cranking up an Athlon
CPUs are often able to run a
bit, or a lot, faster than their sticker speed. They run hotter when they
run faster, and they run hotter still if you increase their supply voltage
to keep them stable, so you generally need more cooling. But the extra hassle
is, for many people, well worth the considerable speed boost you can manage.
500MHz and 550MHz Coppermine P-IIIs, for instance, commonly run perfectly
happily at 700 and 733MHz, respectively - 40% faster than the sticker speed.
To overclock current Intel processors,
you have to wind up their Front Side Bus speed. Their core speed is a fixed
multiple of the FSB - they have a "locked multiplier" - so increasing the
FSB is the only way to go.
Because various other bits of
the computer also have their speed more or less tied to the FSB, this is
not the most elegant way to wind up your CPU.
Athlons also have a multiplier
that can't be changed by simple things like jumpers on the motherboard or
a setup program. But, if you pop open the processor's case, you get access
to a little edge connector on the corner of the circuit board. This edge
connector, known to the cognoscenti as the "Golden Fingers" connector, lets
you change the multiplier, and the core voltage the CPU requests, to anything
you like. You just have to plug in a little circuit board that connects
the pins together in the right way.
One such board is Ninja
Micros' FreeSpeed Pro, available in Australia from PC
Index on their CPU products page, here.
It uses 16 little DIP switches to set the speed and voltage settings, and
is only slightly cryptic to set up. It costs $USD52.5.
The FreeSpeed Pro has a standard
hard disk power socket on its reverse side, and a red LED on the other side
to tell you it's getting volts.
Actually getting access to the
Golden Fingers is the tricky part, but it's not very tricky. To do it, you
just have to pop off the plastic portion of the Athlon cartridge; instructions
on how to do this can be found on Ninja Micros' page here.
You can also increase Athlon
clock speeds by boosting the Front Side Bus; the K7M lets you wind it up
far beyond the normal 100MHz. But the Athlon's design means it actually
doubles the FSB speed for its CPU-to-chipset communication, and it will
tolerate very little FSB overclocking. 10% is unlikely. 5% might work. This
is not very exciting.
