Many on-chip features, such as consolidation of voltage regulators and improved power management have helped reduce power draw. The chip also has reduced power leakage and enabled faster throughput, which reduces the stress on CPUs.
For Intel, improving battery life was the top priority as the company tries to break the dominance of ARM, whose processors are used in most smartphones and tablets, said Nathan Brookwood , principal analyst at Insight 64.
"From the very beginning of the [Haswell] development process they had performance-per-watt be a keen design parameter," Brookwood said.
Intel's new Core processors may in fact compete with its own low-power Atom tablet chip code-named Clover Trail, and later on, Silvermont, a more power-efficient Atom chip due later this year.
"They need that to compete with ARM or even Clover Trail products," Brookwood said.
The 6-watt measure comes from what Intel calls SDP (Scenario Design Power), which measures usage of power to dissipate heat in specific usage scenarios such as mobile or touch applications. That differs from the regular measure of the universally accepted TDP (Thermal Design Power), which Intel says may not apply in the case of devices like tablets, which have a fundamentally different design compared to regular laptops. However, companies like Advanced Micro Devices have contested the SDP measurement, saying the TDP was the best way to measure heat dissipation.
Intel officially announced two U-series chips that draw 15 watts of power. The Core i7-4650U runs at a clock speed of 2.9GHz to 3.3GHz, has 4MB or cache and is priced at US$454 for 1,000 units. The $342 Core i5-4350U runs at 2.6GHz to 2.9GHz and has 3MB of cache. Intel officials did not say when Y-series chips would be released, but said 19 U-series chips would be released this year.
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