Overclockers: Get in early!
Originally published 2001 in Atomic: Maximum Power Computing Last modified 03-Dec-2011.
In the last column, I mentioned the less obvious reason to hold off on buying new and exciting computer gear as long as you can stand. Not only does everything get cheaper all the time, but people who buy later can also find themselves getting better, updated versions of the processor, video card or what-have-you that's taken their fancy. Pay less, get more. What's not to like?
There's an exception to this rule, though. One sector of the market finds later, improved, higher-capacity versions of products steadily less and less interesting as they get faster and faster. That market sector is the overclockers.
When you want to run a CPU faster than stock, the best chip to buy is, generally speaking, one of the early models released right after a new flavour of processor comes out. Not after the release of a whole new CPU, necessarily - just an updated core for an existing chip will do, like the Coppermine core for the Pentium III when it first came out, or the Palomino core Athlon when it succeeded the older Thunderbird core, or the Northwood Pentium 4, successor to the original Willamette P4 core.
The reason for this is that new CPU models tend to have considerably more core speed headroom than well-developed, thoroughly speed-bumped models. Late model chips can often be thought of as "overclocked by design"; the manufacturers have already wrung most of the juice out of the core.
Earlier models may run fine at higher speeds, but need too much cooling, at that speed, to be a mass market product. And early model cores commonly aren't consistent - some can manage a high speed, some can't, and they all get packaged with a speed rating they're sure to comfortably handle.
All this is just part of the adventure, for overclockers.
You may need to crank up the core voltage, and you'll probably need considerably more than stock cooling, to get 30 to 50 per cent more speed out of a new-model CPU. But you're much more likely to be able to do this sort of thing with the first model of a line of CPUs than with the last one.
Take the old Pentium II-based Celerons, for instance. The original 300MHz no-cache Deschutes version and the "300A" Mendocino model were famous for having about a four out of five chance of running perfectly happily at 100MHz Front Side Bus (FSB), instead of their stock 66MHz. Which made them into 450MHz processors.
The Mendocino Celeron at 450MHz was the equal of the 450MHz Pentium II, which was the fastest P-II ever made, and far more expensive. Overclocked Celerons were, at the time, spectacular value for money.
As the Mendocino product line developed, though, the overclocking prospects got less and less exciting. The likely ceiling core speed for an air-cooled Mendocino is about 550MHz. Some do noticeably better, but it's not the way to bet. If the stock speed's 500MHz, a ten per cent overclock to 550 is not exactly a performance-hound's dream come true.
The Athlon line's gone through this cycle a few times. The Thunderbird replaced the original Athlon, and had more headroom. Then that got filled up, and the Palomino replaced the Thunderbird, with more headroom. Then that got filled up, and now the Thoroughbred is about to replace the Palomino. Thoroughbred has the same performance at a given clock speed as Palomino, but it's had another die shrink and should be able to run cooler and faster, yet again. Overclockers will, once again, fall on the new core with cries of glee, and try to get themselves a chip running as fast as the consumer chips of six months in the future.
Some people are into overclocking just for the PC-salon tweakiness of it, of course. Water pipes. Peltiers. Lots of fans, neon lights, case windows with faux etched-glass appliques. Value for money be damned.
If you're in it to get speed on the cheap, though, pick your processor with care.
