Chipset Analysis II
Just a little more tech. to get our heads around before we'll look at the board's performance. I've spoken, at length, about the increased memory bandwidth and 800MHz FSB and how these relate to potential performance gains. The Canterwood's MCH (Memory Controller Hub), or Northbridge, duplicates the incumbent E7205's 1000+ pins FCBGA package. With the rise in pins, over the standard single-channel offerings, being largely attributed to the dual 64-bit (4 DIMM) memory routing, it's a complicated affair. What the above picture doesn't show you is that Intel have managed to successfully route all these paths on just a 4-layer PCB. That's important in the context of eventual cost, as most initial Granite Bay-based motherboards required the more expensive 6-layer construction. Optimising the pin layout has allowed Intel to route an entire channel on a single layer. And as a nod to the intended workstation market, the Canterwood also supports ECC (Error Checking and Correction) memory. A must for mission-critical applications.
Potentially, 6.4GB/s of data has to get from system memory to the CPU via the MCH. The Canterwood-based motherboards will use an optimised, faster path for data delivery. Using certain lessons learnt in CPU manufacturing, the very best silicon is chosen for the i875's MCH. Further, the speed improvement primarily arrives via an optimised memory controller. It allows you to skip two clock cycles when interfacing with CPU and system memory (chip select). It improves on standard Intel MCHs by being faster at turning around CPU memory requests and faster when selecting the portion of memory where that request / data is located. A theoretical 2 clock cycle gain. Being able to turn around requests and route data that little bit faster should manifest itself into slightly greater performance. Think of it as a short-cut or Turbo mode. Intel term this technology as PAT (Performance Acceleration Technology).
Carrying on the theme initiated by the Granite Bay chipset, 8x AGP makes an appearance again. The present gains over 4x AGP are debatable, but upcoming texture-heavy games should give a slight boost in performance. The CSA (Communication Streaming Architecture) is shown running of its own dedicated 266MB/s bus, allowing the pre-mentioned full-duplex Gigabit connection
I've used the word optimising a number of times over the last two pages of discussion. This is, essentially, what the Canterwood is all about. Taking the best bits of present chipsets and making them that little bit better. Removing potential bottlenecks seems to have been a design brief to Intel's engineers; a fast memory subsystem and Northbridge, a full-duplex Gigabit Ethernet connection, and optimised controllers all help keep potential performance inhibitors at a minimum.
In technological summary, the Canterwood chipset is characterised by faster, DDR-400-capable dual-channel memory support, an optimised memory path to and from the CPU, a dedicated 266MB/s link to a full-duplex Gigabit Ethernet connection. The all-new ICH5/R integrates a further 2 USB2.0 ports and 2 independent S-ATA controllers. The ICH5R allows one to RAID two S-ATA drives in RAID0 (more on this later). It's an impressive list of features but I felt as if integrated Firewire and Wi-Fi would have reared their heads in the ICH5/R. Perhaps a revision some time in the future ?.
