Intel Westmere 32nm Launch & Clarkdale Core i5-661 CPU Review

H55 Express Chipset Examined

When the Lynnfield platform was launched, we saw the first new 'Ibex Peak' 5-series chipset, the P55 Express. However, the Ibex Peak family also consists of the H55, H57, and Q57 chipsets. Unlike all previous Intel chipsets which featured both a northbridge and a southbridge (eg. X58 Express + ICH10R), the Ibex Peak are one-chip solutions. As such, Intel have come up with the new designation of Platform Controller Hub (PCH). Intel has managed to transition to a one-chip design since all LGA1156 processors have a memory controller and PCI-Express controller built into the CPU package, therefore rending the northbridge obsolete.

The model we are particularly interested in today is the H55 Express. Unlike the P55 Express, this chipset does not natively support dual PCI-Express 2.0 x8 slots for CrossFire and SLI but some manufacturers can add in a second slot for 8x / 8x though at an added expense to the end user. On the plus side, the H55 is one of three chipsets (H55, H57, Q57) that supports the Flexible Display Interface (FDI). This interface allows the IGP in the Clarkdale processor to channel its graphics data to the display controller in the H55 PCH, which can then be outputted via DisplayPort, DVI, HDMI, or the venerable VGA.

On the connectivity front, the H55 supports up to 12 USB 2.0 ports, 6 PCI-E x1 slots, 4 legacy PCI slots, and 6 SATA II ports. This is 2 less USB ports and PCI-E x1 slots than the other four Ibex Peak models. It also features one Gigabit LAN port and HD Audio Technology.

Meanwhile, the PCH communicates to the CPU via the Direct Media Interface (DMI), a 2 GB/s point-to-point connection, which is roughly equivalent to a PCI-E x4 1.0 link. By the way, the DMI is by no means new, it has long been used as the link between the northbridge and southbridge.

Like all modern Intel chipsets, the H55 PCH is manufactured on the 65nm process and it has a low default voltage of 1.0V. As a result of this low voltage, and the simple fact that the H55 does not actually do much, it does run quite cool. It is also tiny. The H55 package size is just 27mm x 27mm, and the actual die is a minuscule 8mm x 8mm as revealed below:


Remember, this chip is manufactured on the old 65nm process. Can you imagine how small it would be if it were manufactured with the 32nm processor? It would be so small that Intel would integrate it into the CPU die, which is exactly what will be done with the upcoming Sandy Bridge microarchitecture.