Intel Sandy Bridge

Chip giant Intel launched 29 new processors on January 2011. Split between mobile and desktop chips, this TekSpek examines the underlying architecture, known as Sandy Bridge, and evaluates where the new processors fit into Intel's consumer line-up.

Second-generation Core architecture

Intel is marketing the new processors as the second-generation Core architecture, following on from the original Core models released in June 2006. The Sandy Bridge chips bring together a collection of new technologies that makes them the most-complete processors released by the company.

Discussing the desktop models in particular, the Sandy Bridge architecture powering the second-generation Core chips is based on Intel's advanced 32nm manufacturing process. All other things being equal, this means that they have two main benefits over older, larger processors: lower power-draw and, over time, cheaper manufacturing costs.

Traditional CPUs have been designed to focus on the processing of instructions provided by the operating system. Newer iterations of chips have increased efficiency by having more physical and virtual cores, as well as doing more work in each clock cycle. However, in the main, all chips have been straight-up CPUs, that is, processors working on particular types of instructions. This has meant that the graphics portion of the PC, which is required to process and output video to a screen, has used a separate processor usually located on the motherboard's chipset or, where powerful graphics have been a must, through a separate video card.

Now, though, Intel is integrating the basic graphics portion required in every PC directly on to the same silicon as the CPU portion. In effect, Sandy Bridge chips are both CPUs and GPUs rolled into one chip, and it's sensible to call them general processors rather than solely CPUs.

New tricks

These new CPU-and-GPU processors include improvements to the both parts of the chip when compared with the previous generation models. The CPU part runs at higher clock-speeds and is endowed with a new feature-set called AVX. This Advanced Vector eXtention addition is implemented to speed-up processing for program instructions that rely on floating-point (math) performance, as found in a number of premium image- and video-editing programs.

The Turbo Boost feature - the ability to run at higher-than-default clocks on certain cores - has also been overhauled for Sandy Bridge. With both the CPU and GPU sharing parts of the same silicon and on-chip last-level cache, Turbo Boost 2.0 intelligently monitors the load for both constituents and then boosts performance - increasing the frequency - where it is needed most. This means that in certain circumstances both the CPU and GPU speeds are increased, as long as they remain within the power-draw limit hard-wired into the chip.

Intel has previously integrated basic graphics on to the same physical package as the CPU, although not on to the same silicon, as per Sandy Bridge, for mainstream desktop parts. The silicon-integrated graphics ship in two varieties - six and 12 cores - and are clocked in at differing speeds, while the exact configuration is dependent upon the particular second-generation Core processor.

Testing shows that it is around 50 per cent faster than the best IGP to date from Intel. Translating into some numbers you can understand, the top-line Sandy Bridge chip's graphics are good enough to play most games at a 720p (HD) resolution with low-to-medium image-quality settings. However, readers looking for serious graphics performance - including lots of image-improving antialiasing and filtering - need to purchase an add-in, discrete card from either of AMD or NVIDIA's retail partners.

But perhaps the most innovative part of Sandy Bridge graphics is the inclusion of a dedicated portion of silicon for video decoding (MPEG2, VC1, H.264 formats) and encoding - the latter now being fully-performed in hardware. Intel dubs this technology 'QuickSync Video' and has encouraged companies such as ArcSoft and CyberLink to release updates to video-editing apps that take advantage of this feature. This media processor significantly reduces the time it takes for transcoding one type of video into another - a DVD to an iPad-compatible format, for example - by also tapping into the integrated graphics' cores.

Stacking up Sandy Bridge

What you see is that in retail form Sandy Bridge arrives in Core i3, Core i5, and Core i7 flavours. All chips have the integrated HD graphics, of course, but are classified into the three families on the basis of cores/threads and the quality of the integrated graphics. It's a little complicated to understand for a novice computer user, but the key takeaway is that a Core i7 chip is better than a Core i5, while a Core i5 is better than a Core i3.

Healthy frequencies and improved graphics translate to an attractive price-to-performance metric for all Sandy Bridge chips. Indeed, the premium processors are good enough to make the existing top-end Intel platform, X58, somewhat redundant. Intel also caters for the enthusiast by providing a couple of multiplier-unlocked Sandy Bridge chips, identified by the 'K' suffix.

New motherboards required

Folks looking to upgrade their current mid-range Intel platforms - P55 chipset-based boards - will be disappointed to learn that the changes in the Sandy Bridge architecture requires a new range of supporting motherboards. The chips transition from an LGA1156 form factor used for the Core 2010 range to an LGA1155. Keeping with Intel tradition, three main chipsets are launched to provide support for the bevy of new desktop chips. P67 boards are the logical successor to present-day P55. These boards offer a broad range of features, including support for two, or more, graphics cards. However, and this is important, they do not offer any means by which the integrated graphics' video can be outputted to external screens.

The H67/61 chipsets provide a cut-down version of P67 and are likely to be presented in a space-saving microATX form factor - making them ideal for home theatre PCs and small-form-factor units. Where these chipsets really shine is through the provision of external ports for outputting video - usually through HDMI, DVI or, now, DisplayPort. Video outputs and a small board go hand-in-hand in enabling system manufacturers to release cheap PCs that take complete advantage of the Sandy Bridge chip's feature-set.

Lastly, Intel is releasing the Q67 chipset for the business user. Ostensibly the same underlying chipset as the H67 it provides additonal security-related features such as Intel vPro.

Summary

Intel's new Sandy Bridge processors now populate the crucial £75-£250 segment through the release of numerous chips. Continuing the branding nomenclature of Core i3, Core i5 and Core i7, the new chips offer more performance than their predecessors - be it CPU or graphics - at the same price. Indeed, they offer a more-rounded package than AMD's CPU-only Phenoms, making Sandy Bridge a good fit for any mid-range system.

The good news for the enthusiast is that the multiplier-unlocked Core i5 2500K and Core i7 2600K offer consummate performance for a relatively modest outlay. The 2600K, in particular, can be recommended to users who were looking to go down the Intel X58/Core i7 900-series path.

A new year begins with a bang from Intel. Coinciding with the release, Scan, as always, has a complete range of the new chips and supporting motherboards.