Understanding Multi-Core Processing

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Quad-core. Dual-core. Parallel processing. Multi-threading. If you know exactly what I’m talking about (and more), this article probably isn’t for you. If, however, you’d like the low-down on the ‘whys’ and ‘whats’ of basic multi-core PC processing, read on.

Single Cores and the Trouble with Tiny

Remember a time when sizing up a processor was easy? Until the mid-2000’s, all you had to do was look at how fast the chipset was and, maybe, read up on stability recommendations if you were considering overclocking that bad boy. Ah, those were the days; what happened?

Too much power per square micron is what happened.

In order to pack more power into every square nanometer of your CPU, engineers at AMD and Intel kept making the transistors on their chipsets smaller and smaller. (As of 2011, Intel’s Xeon E3-1230 CPU features transistors so small that you could pack over 4000 of them into the width of a human hair.) At these incredibly-small scales, physics decides that it doesn’t have to do what the smart fellows in the Intel clean-room say anymore (especially at the voltages required) and the individual electrons inside these tiny wires begin to hop from transistor to transistor without a care in the microscopic world, scrambling and interrupting data flow throughout the processor. This ghostly phenomenon is known as ‘quantum tunneling’ and puts an effective cap on gains in processing power strictly by cramming more power into smaller and smaller components.

Multi-Cores to the Rescue

In order to overcome the headaches of quantum tunneling (and power usage, heat dissipation and other ‘challenges’), chip designers began to look for different ways to provide more CPU power than didn’t rely solely on making a single CPU more powerful. In 2005, both AMD and Intel released their first dual-core processors onto the market and the shift towards multi-processing began in earnest.

What’s so great about having more than one processor?

  • Higher performance at smaller wattages: Less power means less heat, less tunneling and fewer cooling requirements,
  • Smoother application-juggling: Switching between programs is much smoother thanks to an additional processor(s) handling background applications and processes on a completely separate cache,
  • Effortless parallel processing: Load additional web pages, run virus scans and (heck, go crazy) partition your hard drive with a lack of system slowdown impossible on a single-core machines.

I can hear you thinking, ‘This sounds great. Why didn’t CPU-makers switch to dual-core processing years ago?’

That’s a good question. Multi-core processing does have some drawbacks:

  • Doubling your processors does not double your speed: Two processors does not mean 2x the processing power, nor does 3 processors mean 3x. Real-world technical constraints limit increases in processing speed to 90% in an perfect setting, but the average consumer will only see improvements of 30-70% in upgrading from a single core to a dual-core.
  • Requires software and OS optimizations for peak performance: Computer programs and operating systems need to be written with parallel processing in-mind to take advantage of multi-core hardware. Older software often fails to recognize the existence of additional processors and ignores them completely and resource-intense programs that are not optimized for multi-core machines will see little improvement over single-core machines.

What should I be looking for? – Conclusion

The bottom line is that multi-core processing makes CPU comparison-shopping a little more complicated, but don’t feel overwhelmed. Here are some general guidelines to keep in mind:

  • Single core PC’s are inexpensive, but not ‘bad’ – If you’re upgrading from a computer from the 1990’s and are a light PC user (check your email a couple times a week, browse the web for only a few minutes per day, balance your checkbook in Excel or keep it around to do your taxes), then there’s no reason not to pick up an upgraded machine for around $100. If you do more, consider a dual-core.
  • Dual core PC’s are the best bang for your buck – If you use your computer fairly often (browse the web daily, play a video game or two, check your email multiple times per day), then pick up a dual core machine. Low end dual-cores are fairly inexpensive and make a great upgrade and higher-end versions can make decent gaming/professional machines for decent prices
  • Quad core PC’s are for gamers/professional users – If you need one of these, you probably already know it. The more processors you have at your disposal, the more multi-tasking you’ll be able to do without slowdowns and the better your photo/video/3D-editing programs are going to run. Run your favorite games at max-settings and enjoy knowing you probably won’t need another upgrade for years to come.



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