K7OC
I first started fiddling with
the K7OC. This is a small unit, measuring only 57mm across (2
1/4 inches) and 33mm tall (a little over 1 1/4 inches). It has
2 banks of dip switches, one with 8 switches and the other with
4. It is also the first overclocking board I've seen with all
the right stuff on it according to the schematics at www.tomshardware.com,
all the others I've seen have used regular resistors instead of
SMD packs, and diodes instead of a voltage regulator. This isn't
to say that the latter isn't capable of doing just as good a job,
but they do take up more space, and small is what we want this
thing to be. On top of this, the K7OC uses 220 ohm resistors instead
of 56 ohm, which leads to lower heat being produced. As we all
know, we want to keep our overcooked CPU's as cool as possible
so this is an added bonus. It also has a power connector wired
up to it with a pass-thru so you don't have to waste any precious
power connectors to run it. The dip switch settings for the K7OC
are repeated on the back of the PCB, which is good for those of
us (like me) who are prone to losing the sheets of paper that
things come with.
Once I had the CPU out of its plastic case and set the dip switches
on the card it was a simple matter to plug it in. At least I thought
it was! Which way does it go? It fits both ways, there is no key
stopping incorrect orientation. I rang Agg to see if he had any
extra instructions but he didn't. Commonsense told me that it
would fit in such a way that the bulk of the PCB wasn't hanging
off the side of the CPU, and that's the way it goes as I found
somewhere. I think I ended up finding out via a picture on a website,
there doesn't seem to be any specific instructions on the K7OC
website other than "plug it in". The retail product
probably comes with full instructions detailing which way it goes,
but all I got for the review piece was the card and jumper settings
on a piece of paper.
I decided to be bold and set my
Athlon 500 to 700MHz. I put the CPU back in the case after connecting
the power to the k7oc and booted up. It got most of the way through
a Windows 98 boot before it did a cold reset. "Not to worry"
I told myself, "It just needs more volts". So off came
the card and I bumped the voltage up to 1.70. This time Windows
booted up fine, and I set it up for some torture testing.
After about 24 hours of torture testing I didn't get any errors,
but since then I got the occasional blue screen or system crash
(especially during Counter-Strike) which told me that my CPU didn't
like that speed (at least with my VEK32 cooler). I decided to
bump it down to 650 and since then it's been much more stable.
I also took the voltage down to 1.65, but it seems more stable
at the default 1.6 volts for some reason (probably due to less
heat, or else it's my imagination). Still, 650MHz out of a 500MHz
CPU at default voltage when the cooler is only rated to 600 and
the case isn't rated to anything is pretty good. I'm more than
happy with this speed, and I'll try for 700 again when I get a
better cooler.
The K7OC is a neat unit, it does everything that is claimed as
well as being over-spec in the resistor department to keep the
heat down. The one I have has dodgy power wires going to it though,
they are slightly frayed on top and could have led to a short
if I didn't neaten them up. This could be just a one-off though,
it's no big deal as long as you double-check it before installing.
