Unlike our watches that tick-tock thirty times a minute, Intel has tweaked their clock so that it tick-tocks twice a year, in order to, among other things, remind us that it's time for improving existing technology. This year's “tock” brings us a new microarchitecture, codenamed Sandy Bridge. We've already covered the theoretical aspects of Sandy Bridge in two separate articles recently; well, perhaps not theoretical, but certainly without a tangible model in front of us to provide us with first-hand results. The previous articles were based on the information released to the public by Intel, as well as some that found their way out in spite of Intel's will. The time has finally come for us to see whether the words of Intel's representatives about energy-efficient performance, major advancements in the graphics field, Turbo Boost technology optimisation etc. ring true and are truly based on actual results.

Owing to improvements and technical solutions offered by the second generation of Intel Core CPUs, the jump compared to current CPUs should be a major one, in terms of both raw performance and architecturally. As a reminder, the new Sandy Bridge microarchitecture retains the 32 nm production process, but also integrates a lot. The CPUs from the current Core generation had the IGP (integrated graphics processor) made in the 45 nm production process, physically separate from the core, using the QPI link to communicate with the CPU. Well, now it's no longer an integrated GPU, it's a graphics core that consists a part of the CPU - CPU graphics, so to speak. Improvements were made the following way, as usual, in many fields and levels:

• An optimised Loop Stream Detector has been presented, which, combined with additional microoperations cache, enables better performance and lower consumption
• The branch predictor has been completely redesigned, making the new version of this module more CPU-efficient, which results in more precise branch prediction, making a direct impact on CPU performance.
• As ever, Intel is still pushing AVX (advanced vector extensions) forward as standard, which means that Out of Order (OoO) extensions had to get improved hardware to adequately accept and process them (they can now come as 256-bit operands, unlike the 80-bit ones in the previous generation), which led to Physical Register File being presented.
• System Agent represents all that used to be located in the northbridge: PCI Express, memory controller, display engine, consumption control unit... System Agent has a microcontroller regulating consumption on chip level, with separate units for the graphics section, the cores and System Agent itself. By allowing separate voltages and frequencies for the cores/memory bus and the graphics subsystem, System Agent should be one of the main factors to influence consumption in mobile platforms, and therefore a bliss for battery life.
• One of the greatest advantages that the new architecture promotes is the revised LLC, or L3 cache memory. In the previous generation, the cores had direct access to L3 cache, while the GPU had its own memory. With Sandy Bridge CPUs, we have the Ring bus, a circular bus that connects the LLC to the cores, graphics subsystem and System Agent, which means that it's commonplace for all. The clock of the bus itself, and therefore the entire LLC, is determined by the CPU, and like everything in Sandy Bridge CPUs, it's dynamic, changing depending on the needs for processing power or graphics usage.
• As we've already mentioned, the GPU is now an integral part of the chip and connected with the rest of the system by a fast memory bus, which has reduced latencies - information no longer has to be transferred to RAM and back, since everything is now kept inside the CPU itself. Not only does this provide better performance, but it also saves power. All Sandy Bridge CPUs have a graphics subsystem, and the desktop platform will have access to either HD 3000 (12 EUs) and HD 2000 (6 EUs). Of course, the difference lies in frequencies as well, and the weakest version of Pentium and Celeron CPUs have a combination of HD 3000 and HD 200 with 6 EUs and certain additional limitations, mostly tied to encoding/decoding video. In mobile platforms, all CPUs have 12 EUs for graphics processing, and the differentiation is done based on their clocks.
• The media engine is one of the important elements of CPU graphics, in charge of processing multimedia. So far, this section was assigned to EUs, but now there are separate sections in charge of processing multimedia exclusively, with particular attention paid to video.
• Turbo Boost has also had a fair share of improvements. First of all, the technology is now called Turbo Boost 2, and rightly so, since the improvements are obvious and felt. Turbo Boost is no longer limited to one or two cores - all cores can now be overclocked if there is a need for such a thing. Also, Turbo Boost 2 enables the CPU clocks to be clocked outside of the range of the TDP, but in smaller time intervals, in order to give extra juice for better performance over shorter stretches. This is done by accumulating thermal budget while the CPU/graphics are in idle state, which also determines the available amount of time that Turbo Boost can remain active for.
• Overclocking, at least the way we know it, is done, at least as far as Intel's concerned. Sandy Bridge CPUs will allow no overclock, at least not the typical way, because of the architecture's limitations and the removal of the clock generator from the CPU itself. Intel reckons that Turbo Boost will serve for this purpose just fine. Somewhat more serious overclocking will be possible, but only with the unlocked, “K” CPU series, while Turbo Boost remains the only available compromise for those with a cheaper ticket.

The new CPUs can be recognised by the number “2”, standing in front of the product name, which signifies that you're dealing with a second-gen Intel Core CPU, while the corresponding chipsets with LGA 1155 sockets for new CPUs will be named P67, H67 etc. The aforementioned “K” suffix is there to distinguish models with unlocked multipliers. We received three new CPUs for testing the new architecture: Intel Core i7 2600K, Core i5 2500K and i5 2400, two Intel motherboards: DP67BG (codenamed Burrage) with the P67 chipset and DH67BL (Bearup Lake) with the H67 chipset, as well as two cooling solutions: Intel BOX cooler for Sandy Bridge, and Intel Thermal Solution XTS100H, already presented as the cooling solution for the strongest Intel CPUs from the previous generation.