Additionally, the designers improved the memory interface by switching from four standard DDR2 memory interfaces to four dual-channel, fully buffered (FB) DIMM controllers. Able to operate at 533 MHz, the FB-DIMM channels improve the memory system bandwidth and provide a larger memory capacity--key for getting the most out of the server.
Math performance was also spruced up, via an improved floating-point unit, and the data encryption capability was accelerated with the addition of a cryptographic coprocessor that includes a modular arithmetic unit and a cipher/hashing unit.
Further, to reduce the component count in server and blade-server applications, the designers incorporated two 10/1-Gbit/second Ethernet ports, with on-chip packet classification and filtering capability, as well as one PCI Express eight-lane interface, to offer a high-speed periph- eral channel for graphics or other functions.
In the server space, dual-core Xeon processors based on the Netburst architecture are still being introduced, even as versions based on the Core microarchitecture, such as the Woodcrest processor, begin sampling.
The just-released Tulsa processor, able to run four threads per core, illustrates what Intel can achieve with the Netburst architecture, developed for the Pentium 4. The Tulsa contains two Netburst-capable cores that can run at 3.4 GHz. Each core can execute four threads when the hyperthreading capability is enabled.
Implemented using Intel's latest 65-nm process, the Tulsa chip also packs an extremely large, 16-Mbyte shared Level 3 cache, in addition to dedicated 1-Mbyte Level 2 caches on each of the two cores. The high clock speed keeps the power consumption per core at about 65 W, which is about 20 to 40 percent lower than the previous-generation dual-core Paxville processor. Nonetheless, the 130-W total power consumption for the Tulsa, although manageable, puts the chip at the upper edge of what is considered practical for most commercial systems.
In total, Intel has already released more than two dozen dual-core processors, and more dual-core and quad-core processors are on the way into 2007.
The original Pentium D processor for desktop systems has been superceded by CPUs based on the recently released Core microarchitecture for laptops (Merom) and desktops (Conroe). Now referred to as the CoreDuo processors, those CPUs are supported by a full infrastructure of chip sets and software tools to aid in the development of multiprocessor and multithreaded applications.
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