Compaq ProLiant 6500 Compaq ProLiant 7000 Server Technology - Page 4

TECHNOLOGY BRIEF (cont.) Pentium II Xeon (Slot 2 cartridge) Pentium II (Slot 1 cartridge. ECG078/0698 ... Larger Cache Sizes The Pentium II Xeon processor supports larger L2 caches than previous Intel processors. Pentium II Xeon processors are initially available in 512-KB and 1-MB configurations with future plans for a 2-MB cache. In contrast, the Pentium Pro processor has a maximum 1-MB cache. The larger data cache provides a significant performance boost, especially in symmetric multiprocessing (SMP) configurations and systems used in memory-intensive applications, such as on-line transaction processing. Full-Speed L2 Cache Bus Previous Pentium II processors have a half-speed L2 cache bus that connects the cache memory and the central processing unit (CPU) core. This means a 266-MHz Pentium II actually transfers data between the L2 cache and CPU core at 133 MHz. In contrast, the Pentium II Xeon processor has a full-speed cache bus, which means that a 400-MHz Pentium II Xeon processor transfers data between the L2 cache and processor core at a full 400 MHz. The combination of the fullspeed cache bus and the larger cache size greatly enhances the performance of the Pentium II Xeon processor relative to the Pentium Pro and previous Pentium II processors, especially in larger SMP configurations and memory-intensive applications. Slot 2 Cartridge Pentium II processors are packaged in a single edge contact (SEC) cartridge. The SEC cartridge for a Pentium II processor inserts into the Slot 1 connector on the motherboard, while the Pentium II Xeon's SEC cartridge inserts into the Slot 2 connector. The form factor of the Slot 2 cartridge is larger than that of the Slot 1. Compared with the Slot 1 cartridge, the Slot 2 cartridge has • More pins (330 pins versus 242 pins for the Slot 1). • Support for a four-processor multiprocessing bus. • Load and signal integrity modifications. • The ability to deliver more power to support the larger, full-speed L2 cache. The larger cartridge and corresponding motherboard connector for the Pentium II Xeon processor require more pins. The additional pins on the Slot 2 cartridge provide support for a fourprocessor (4P) multiprocessing system bus. Load and signal integrity modifications in the new design allow a Pentium II Xeon processor to drive up to four main loads on the AGTL+ bus- three other processors and a memory and I/O controller. This allows the Pentium II Xeon to scale to 4P configurations. The extra pins also provide the additional power and ground connections needed to support the larger, full-speed L2 cache. 64-GB Cacheable Address Space The Pentium II Xeon processor is able to access up to 64 GB of RAM; however, the memory controller chipset determines the actual size of supported memory. Initial Pentium II Xeon chipsets support memory configurations up to 8 GB. MMX Technology The Pentium II Xeon processor supports MMX instructions, which allow certain applications to operate on multiple data locations with a single instruction call to the processor. The MMX functions are primarily used in multimedia applications such as audio and video manipulation; however, increasing numbers of specialized business applications are being written to take advantage of MMX capabilities. 4