Intel Pentium III 1000S socket: Socket 370

What the Pentium III 1000S is

The Intel Pentium III 1000S is a 1000 MHz single-core server processor from June 2001. It runs one P6 Tualatin-S core at 1000 MHz with no turbo, so 1 core gives 1 thread. Cache is 512 KB of full-speed L2 with 32 KB of L1 on a 130 nm process. Power is rated at 30 W in a Socket 370 FC-PGA2 package with part number SL5PS on a 133 MHz front side bus with a 7.5x multiplier at 1.475 V.

The S suffix marks double cache over desktop Tualatin 1000 parts with the same clocks, which is why the 1000S suits cache-sensitive server tasks while sharing boards with desktop Tualatin chips. Intel placed the 1000S in June 2001 with the 1133S server parts. The chip supports MMX, SSE and dual-processor operation on server boards.

Double cache with a modest envelope suits entry Socket 370 servers with SDRAM and PCI expansion. The 512 KB Advanced Transfer Cache trims memory stalls in file tasks. That is why the 1000S shipped in low-profile rack boxes with ECC memory paths.

Socket and motherboard compatibility

The 1000S fits Socket 370 server boards with Tualatin-S support. It needs a 370-pin FC-PGA2 server board with a 133 MHz bus and a BIOS that lists Pentium III-S parts. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

Entry server towers with ServerWorks paths are the natural match. Boards listing Pentium III 1000S accept the chip with a 30 W cooler and ECC DIMM paths. Desktop-only boards with no S strings may run it as a desktop chip, but dual operation needs a server board.

Memory, PCIe and cooling

Memory is PC133 ECC SDRAM through the board chipset, matched to the board DIMM sockets. The CPU has no memory controller, so the chipset sets ECC support and speed. Server boards commonly run ECC pairs for S parts.

A 133 MHz front side bus ties the CPU to the chipset, while PCI and AGP hang off the chipset. No PCIe lanes originate on the die. Cooling uses the Socket 370 lug clip on the FC-PGA2 spreader with a cooler rated for 30 W and steady front-to-back airflow.

Upgrade paths

On the same socket, a move to a Pentium III 1133S such as Intel Pentium III 1133S keeps the board and memory when the support list names it. The 1133S adds 133 MHz at similar power with the same 512 KB cache, so the cooler carries over. A Pentium III 1000 such as Intel Pentium III 1000 halves cache to 256 KB and is a step down for server tasks.

A move to Pentium III 1266S keeps the server path with higher clocks when power tables allow. The Socket 370 page lists the Tualatin server range for planning.