Core i7 CPU

Hyper-Space Threading
Hyper-Threading was one of the major points of contention back in the days of the (now ancient) Pentium 4 era. It is a function of the hardware to analyse code, and to locate any repetitions that happen multiple times (the Loop Stream Detector takes care of this). These repetitions are then split into two threads, and pumped concurrently to a single CPU core. The reasoning behind this is that the core is never left idle between instructions, and can work through the code more efficiently. This is why you’ll notice that Windows detects Nehalem as being an Octal-threaded Quad-core CPU. Applications that take advantage of this tech the most are video encoding and editing, as well as intense scientific calculations.

QPI – A whole new FSBallgame
You’re probably familiar (if not intimately so) with the FSB. The FSB, or Front Side Bus, is a method of connecting all the components on a motherboard with each other. This has been used in all Intel motherboards up until this point, and has proven to be a limiting factor in increasing performance, bottlenecking the amount of data that can be worked upon. It is also not very extensible, as each CPU or component added to the system takes a slice of the total bandwidth available, reducing the benefits of having two. The FSB also requires a very high frequency (333MHz is very common), and can place stress on some motherboard components. It’s essentially an outdated tech, which has spurred on the evolution of the FSB’s replacement – the QPI.

The QPI, or Quick Path Interconnect, is similar to AMD’s HyperTransport, or HT bus. The HT bus is a bi-directional parallel link, and the last standard (3.0) provides a theoretical bandwidth of just over 40GB/s per second. QPI, along much the same lines, provides multiple links between each core of the CPUs, memory, and all the components on the board. Since this is not shared, each link is free to operate at the full bandwidth, allowing a core on another CPU access to memory data at a very fast speed. Current theoretical performance on an X58 motherboard of the QPI is just over 25GB/s. This might not sound like it’s as good as AMD’s, but here’s the kicker – this is between every major component on the board, in any direction, at any time. In terms of real-world usability and viability, the QPI is a significant improvement, and Intel will surely encroach heavily on the Server market once these chips become available.