Since the launch of Intel’s Core 2 series of processors, Intel has held the performance crown all the way till today. Even though the Core 2 processors were really quick, Intel apparently decided that it wasn’t fast enough, and hence came along the Core i7. The ‘Bloomfield’ Core i7 (Nehalem) ran on a triple-channel memory controller to provide impressive memory bandwidth results. Not only that, the Core i7 also excelled in CPU-intensive applications, as well as games; virtually anything thrown at the Core i7 was demolished.
Intel Core i7 860
For our gaming rig build, we have opted for one of Intel’s latest Core i7 processors, the Core i7 860. It is a 2.8GHz quad-core processor, and supports Hyper-Threading, giving it eight working threads. The i7 860 is part of the 45nm quad-core mainstream Nehalem family, also known as Lynnfield. There are another two Lynnfield processors – the i5 750 and the i7 870. Lynnfield requires a new processor socket: LGA 1156. The increase in number of pins is necessary as Intel has shifted both the memory controller (supports dual-channel) and the PCI Express controller onto the processor itself.
One of the most interesting features of Intel’s Lynnfield processors is Turbo Boost. Well, the previous time you ever heard of the word ‘turbo’ would probably be in the 486 and Pentium era. Turbo Boost is present in the LGA 1366 ‘Bloomfield’ processors, but performance gain was still a little desired due to minimal increase in clock speeds. Whereas for the case of Lynnfield, the Turbo Boost speeds are ramped much higher thanks to improved wafer over the past year.
For example, assuming all things equal, if you had a 3GHz single core processor and a 2.5GHz dual core processor, both running the same single-threaded application, the single core processor would get the job done faster simply because only one core is utilised, and the former is clocked faster. With a Lynnfield, the other three cores are powered down because this is a single-threaded application, but at the same time, the active core is clocked higher, all the way up to 3.6GHz depending on the processor model – so now if you pit the same 3GHz processor against the i7 860, the latter is expected to complete the single-threaded task faster under most circumstances.
Here’s a table of how fast you can expect these Lynnfields to run with Turbo Boost according to how many cores are currently active.
3 or 4 active
Core i5 750
Core i7 860
Core i7 870
As noted briefly before the table, there might be instances where Turbo Boost may not work up to expections as it depends on what type of instructions are being passed to the processor. Also, while Turbo Boost is activated, the processor still has to adhere to its 95W TDP limit.
Intel P55 Express chipset
Chipsets such as the Intel P45 Express and earlier are based on a two-chip design. The memory controller hub (MCH), also known as the northbridge, handles data between the processor, memory, and graphics card(s), while the I/O controller hub (ICH), known as the southbridge, handles the other stuff like USB and storage. The processor and the MCH are linked via the front side bus, and this bus only has a maximum bandwidth of 1600MT/s. With processors becoming so fast today, FSB bandwidth bottlenecking may occur simply because the processor has enough power to execute instructions faster than the rate data is being brought in from the memory and graphics components.
Since the Lynnfield now sports on-die memory and PCIe controllers, the MCH and FSB link is not needed anymore, and effectively removes bottlenecking due to bandwidth limitations. Naturally a new chipset is required to pair with the Lynnfields. Known as a Platform Controller Hub (PCH) now, the Intel P55 Express chipset is a single-chip southbridge design. Notice that the northbridge is no longer present, and the P55 Express chipset connects directly to the Lynnfield processor via DMI.
In short, the Lynnfield and P55 combination is a much faster, efficient and meaner platform than the previous generation.