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Intel Turbo Boost vs. AMD Turbo Core Explained
An anonymous reader recommends a PC Authority article explaining the whys and wherefores of Intel Turbo Boost and AMD Turbo Core approaches to wringing more apparent performance out of multi-core CPUs. "Gordon Moore has a lot to answer for. His prediction in the now seminal 'Cramming more components onto integrated circuits' article from 1965 evolved into Intel's corporate philosophy and have driven the semiconductor industry forward for 45 years. This prediction was that the number of transistors on a CPU would double every 18 months and has driven CPU design into the realm of multicore. But the thing is, even now there are few applications that take full advantage of multicore processers. What this has led to is the rise of CPU technology designed to speed up single core performance when an application doesn't use the other cores. Intel's version of the technology is called Turbo Boost, while AMD's is called Turbo Core. This article neatly explains how these speed up your PC, and the difference between the two approaches. Interesting reading if you're choosing between Intel and AMD for your next build."
...Turbo switches on our workstations again like back in the day?
That read like the pasting of two press releases together. That did very little to explain what is going on beyond press grade buzz words.
The article kinda glosses over things. So a more detailed explanation of how Intel's turbo boost works:
As stated, every core has a budget for the maximum heat it can give off, and the maximum power it can use, as well as a max clock speed that it can handle. However, when you look at these things, they aren't all even, one ends up being the limiting factor. So Intel said, ok, we design a chip to always run at a given speed and stay under the thermal and power envelopes. However, if it isn't running at that, we allow for speed increases. It can increase the speed of cores in 133MHz increments. If things go over, it throttles it back down again.
This can be done no matter how many cores are active, but the less that are active the more it is likely to be able to be. On desktop cores, it isn't a big deal since they usually run fairly near their speed limit anyhow. So you pay see only 1 or 2 max 133MHz increments that can happen. For laptop cores, in particular quad cores, it can be a lot more.
The Intel i7-720QM runs at 1.6GHz and has 1/1/6/9 turbo boost multipliers. That means with all 4 cores running, it can clock up at most 1 increment, to 1.73GHz. However with only one running, it can go to 2.8GHz, 9 133MHz clocks up. It allows for a processor that would be too fast to reside in the laptop to go in there with some flexibility. A desktop Core i7-930 is 2.8GHz with 1/1/1/2 turbo mode. That means it'll clock up to 2.93GHz with 2-4 cores active, and 3GHz with 1. Much less flexible, since it is already running near it's rated max clock speed.
Now this is not the same as speed step, which is their technology to down clock the CPUs when they aren't in so much use. Similar idea, but purse based on how hard the CPU is being asked to work, not based on if the system can handle the higher speeds.
As an aside, I'll call BS on the "Little uses multiple cores." Games these days are heavily going at least dual core, some even more. Reason is, if nothing else, the consoles are that way too. The Xbox 360 has 3 cores, 2 threads each. The PS3 has a weak CPU attached to 7 powerful SPUs. On a platform like that, you learn to do parallel or your games don't look as good. Same knowledge translates to the PC.
However there are still single core things, hence the turbo boost thing can be real useful. In laptops this is particularly the case. If the i7 quad was limited to 1.6GHz, few people would want it over one of the duals that can be 2.53GHz or more. Just too much loss in MHz to be worth it. However now, it can be the best of all worlds. A slower quad, a faster dual, whatever the apps call for, it handles.
There are a multitude of aftermarket CPU coolers which are much quieter than the stock ones from Intel or AMD. Some chips can even be run passive with the right heatsink. Take a look at the reviews on http://www.silentpcreview.com/