NEC HX4500 manual Processor, Memory, Bus Master I/O Expansion Slots, Real-Time Clock/Calendar

Processor

Each Pentium II Xeon processor is packaged in a single edge contact (S.E.C.) cartridge. The cartridge includes the processor core with an integrated 16 KB primary (L1) cache; the secondary (L2) cache; a thermal plate; and a back cover. The cartridge is secured by a retention module attached to the baseboard. Depending on configuration, your system has one to four processors (see Figure 1-7). Additional Pentium processors enhance performance and enable symmetric multiprocessing (SMP). All processors access the same memory and I/O space and tasks can run on either CPU if your operating system (OS) supports SMP.

Memory

The Memory board contains sixteen 168-pin DIMM sockets (see Figure 1-8, A and C). A minimum system configuration includes 128 MB (using four 32 MB DIMMs) of system memory. Sixteen DIMM sockets allow for system memory expansion up to 4 GB (using sixteen 256 MB DIMMs). ECC generation/checking is provided for detection and correction of memory errors.

Note: Only use DIMMs approved for use in this server system. Call your customer service representative for information.

Bus Master I/O Expansion Slots

The server's expansion capabilities meet the needs of high performance I/O servers by providing a combination of PCI local bus and ISA connectors. The system I/O board offers nine dedicated PCI slots and two dedicated ISA slots.

The system I/O board contains two ISA bus master I/O (input/output) expansion slots (see Figure 1-6, C). The ISA architecture supports 32-bit memory addressing and 16-bit data transfers for the CPU, DMA, and bus masters.

The system I/O board also contains nine PCI bus master I/O expansion slots (Figure 1-6, A, B, and E).

Real-Time Clock/Calendar

The real-time clock provides system clock/calendar information stored in a non- volatile memory (NVRAM). The real-time clock battery (see Figure 1-6, Q) provides power backup for the real-time clock.

BIOS

A BIOS and Setup Utility are located in the Flash memory (see Figure 1-6, R) on the system I/O board and include support for system setup and PCI/ISA Plug-and-Play auto-configuration. A number of security, reliability, and management features are also incorporated to meet vital server needs.

1-16 System Overview