Core i7 CPU

Memory Interface
Traditionally, Intel systems would include the CPU, Northbridge, and memory, with the memory controller (the part that coordinates and facilitates memory communication) located in the Northbridge. This was a slow method, causing large amounts of latency (the time it takes to get the information from the memory to the CPU). Intel has now created an on-die memory controller, moving this part of the system out of the Northbridge. Using DDR3 memory only, this eliminates the need to access through another chip, and drops the latency by half, at the same time increasing bandwidth.

Not only that, but the memory controller has been upgraded, providing three channels of bandwidth with the system memory for theoretically up to 32GB/s. This is a massive increase over the previous Northbridge solution, and takes a leaf from AMD’s book (whihc has moved its memory controller onto the die some years previously).

Comprehensive SSE Support
With an updated architecture and platform, this also brings to the table updated support for all the latest instructions. A set of SSE instructions are a list of sorts that enables the CPU to understand and work with specific kinds of code more effectively. Nehalem supports all the SSE instructions up to and including 4.2, offering enhanced support for video codecs and encoding, with specific acceleration for Voice Recognition and DNA sequencing. It’s obvious that Intel would love for its chips to be powering the future technologies, and with forward-thinking support like this, it’s in the best position to take advantage.

Turbo mode, Engage!
The TDP (Thermal Design Power) of Nehalem is 130 Watts, which means that they are designed to make that much heat under heavy load. The problem with most applications today is that the CPU isn’t stressed across all four cores, leaving room for extra speed. Turbo mode provides that extra speed, actively increasing the multiplier of the CPU on-the-fly to provide a speed bump of a few hundred MHz while still remaining inside the TDP.

Of course, increasing all four cores is great when you’ve got a multithreaded application, but what if you’ve got a single threaded app? Well, those crazy boffins at Intel thought of that too. In the event that a single core is furiously working through a particularly demanding application, and the other cores are idly sitting there wasting power, Turbo mode can effectively power these idle cores down and increase the speed of the single core – and stay within the TDP – increasing performance in these applications when needed. This alone is probably the most important trend that we’ll see developing in the CPU design world, where the hardware itself will attempt to make allowances for inefficient or single-threaded programming.