You can buy pre-overclocked hardware.
For graphics, Best Buy has recently been advertising factory-OCed
VisionTek Radeon HD 3870 cards
(
http://www.bestbuy.com/site/olspage.jsp?skuId=8762234&type=product&id=1
203815034383 ). Other graphics card makers have similar offerings.
Indeed even if your graphics card is not factory-overclocked you can
download RivaTuner (nVidia & ATI) or just use the ATI-supplied Catalyst
Control Center to play with GPU clock speeds.
For CPUs, the big players don't generally offer factory-OCed systems but
there are smaller players that do. They typically cater to the gamer
market where the customer base likes tricked out systems. A lot of
these systems have over-the-top cooling as an additional
marketing/profit point.
Note that in both cases we have to assume that the card/PC seller is
warranting the OCed components and that Intel, ATI, or whoever makes the
actual chips is not.
Chips are tested at the highest markets CPU speed/bus multiplier. If it
fails, they test at the next highest and so on. Once it passes QC they
mark the chip for that speed & send it on to packaging.
Again, though, as Lukas mentioned sometimes market dynamics cause chips
that pass QC at higher speeds to be marked as lower speed. Case in
point: A few years ago AMD was producing their Athlon XP lineup. The XP
1700 was selling for around $50. Higher speed chips like the XP 2600
were running closer to $200. And AMD was blessed with getting very good
production yields; lots of chips were passing QC at higher speeds. But
a 1700 was a decent chip and in order to meet demand AMD took 2600s and
sometimes 2700s and stamped them as 1700s. The interesting thing about
their stamping at the time was that it included both the marketed speed
and the QC-pass speed.
Well, of course word got out. I bought a 1700 that had passed QC at
2600 so I got a $200 CPU for $50. I immediately ran it at 2600 with no
problems. Then I overclocked that and ran it as a 2900 using stock
cooling. I'm sure it would have gone faster with better cooling & a
voltage bump but I didn't want to risk frying the chip.
midrange.com
