Original URL: https://www.theregister.com/2010/09/13/idf_intel_sandy_bridge_turbo_boost/
Intel 'Sandy Bridge' to sport 'next-gen' over-clocking tech
Bursty for better performance, lower power consumption
Posted in Personal Tech, 13th September 2010 22:54 GMT
IDF Like today's Core i5 and i7 processors, Intel's 'Sandy Bridge' architecture, their successor, will incorporate TurboBoost, a technology that allows the chip to temporarily run at a higher clock speed than the one it's rated at. But the new chip design's implementation of the technique improves on the old one in a number of important ways.
The first is what Intel engineers claim will be "significantly" greater headroom for over-clocking. They're not stating numbers, so we'll have to see how much higher the new CPUs will run above their rated speeds.
However, this higher headroom derives from the design's greater degree of integration which, in turn, allows the chip's power management sub-system more scope to average out the power use across the parts that need it and those that don't.
Having a more holistic view of the chip's power usage allows some tricks to be implemented. A case in point: TurboBoost can (briefly) take the frequency above the TDP. And if the chip has been idling for a certain time, when there's a sudden demand for performance - the user has double-clicked on an application's icon, for example - Sandy Bridge knows it can ramp up the clock speed considerably for 20 seconds or so before heat becomes a problem.
That can be just enough to stop the computer from becoming unresponsive, for example when the user quickly performs another tasks while waiting for the double-clicked application to load.
After 20-25s, the CPU drops down to its rated clock speed, but the burst of speed may well have been sufficient to keep the system responding smoothly and immediately to what the user is doing.
Sandy Bridge's design team also added more rungs to the ladder of clock speeds up which each core can ascend. That again makes for better averaging of the power consumption across cores, which can now be over-clocked simultaneously. Previously, the degree of over-clocking depended on the number of cores in play. Four simultaneously running cores would be over-clocked to a lesser extent than one core alone might be.
And not just the CPU cores. Because Sandy Bridge's graphics unit is fully integrated - current Core i5s and i7s simply have a GPU that's been mounted inside the CPU packaging - the chip's power management system can take its usage into account too, dynamically applying its power budget to the CPUs when the GPU isn't being utilised and vice versa.
Sandy Bridge's incarnation of TurboBoost can up the GPU's clock speed too.
As before, the reason for increasing the clock speed is to provide extra performance when it's required, allowing work to be completed more quickly so the CPU can enter a low-power state sooner. While running a core at a higher-than-rated clock speed increases power consumption for the duration, getting the job done sooner uses up less power overall.
Laptops and desktops based on Sandy Bridge Core CPUs will be out early next year. ®
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