Sandy Bridge processors have earned their right to be called revolutionary development of Core microarchitecture not only due to their very high performance. They have also offered users better performance-per-watt. This immediately bumped up the battery life in contemporary mobile computers, making the dreams of a notebook that won’t need to be recharged for the entire day much more realistic. Moreover, it is Sandy Bridge microarchitecture that should create an entire new class of portable devices called ultra-books, which will combine the major advantages of tablets with those of classical notebooks. In other words, contemporary processor microarchitecture had a tremendous effect on the development of the mobile market.
However Sandy Bridge energy-efficiency affected not only the features of contemporary notebooks. It also played an important part in the desktop segment, too. It is due to energy-efficiency that Intel was able to roll out an entire desktop processor family with low power consumption. These processors found their way into a specific type of home systems called Lifestyle PCs, which combine the functionality of an HTPC with that of a compact and quiet home system, a mono-block, etc. Of course, we can’t say that Intel couldn’t offer anything like that before Sandy Bridge. However, it is a known fact that desktop processors with low TDP used to be rare and exclusive products. Now things have changed dramatically. Side by side with the regular desktop processors with 95 W and 65 W TDP, Intel expanded their product range with two complete product series featuring lower 65 W and 45/35 W TDP. And these processors, just like their “regular” brothers, have a pretty fast Intel HD Graphics core, which allows doing without a discrete graphics card in many energy-efficient systems.
Of course, energy-efficient models are slightly inferior in features and functionality to regular processors, which do not focus on low power consumption and low heat dissipation. But nevertheless, we can’t say anything bad about their performance, because they are still fast enough according to today’s standards. The table below shows the distribution of nominal clock speeds in regular and energy-efficient series.
* - Dual-core 35 W model with 2.7 GHz frequency
formally belongs to the Core i5 series.
The clock speeds of regular processors are on the pink background. The blue background indicates the frequencies of energy-efficient S-series CPUs with TDP lowered to 65 W. Light-green color indicates the frequencies of the T-series processors from the most energy-efficient series with 35 W or 45 W TDP.
In other words, S-series offers energy-efficient modifications of the fastest Sandy Bridge processors and ensures a 30% power consumption drop at the expense of 20% of the clock speed. T-series offers more dramatic energy savings, but at the same time it doesn’t include any quad-core processors with Hyper-Threading support, and the clock speed may be 25-30% lower compared with regular CPU models.
Today we are going to check out the most interesting energy-efficient processors – the T-series CPUs. Their TDP is so low that they can be used in the smallest Mini-ITX cases and be part of quiet fanless systems. Since their integrated Intel HD Graphics core in most cases replaces the external graphics card just fine and the power consumption of the chipset for Sandy Bridge platforms is only 6.1 W, a complete system with a T-series CPU inside may easily be powered by a 60 W PSU and in this aspect get very close to contemporary mobile platforms. However, the question is: how much of performance will the users sacrifice in the end for the sake of this economy? We will do our best to investigate and address these concerns in our today’s article.