Intel Xeon MP 2.83 socket: Socket 604

What the Xeon MP 2.83 is

The Intel Xeon MP 2.83 is a single-core multiprocessor server processor that reached the market in March 2005. It pairs one NetBurst execution core with Hyper-Threading, so the operating system sees 2 threads from the single core. Clock speed is 2.833 GHz through a 17x multiplier on a 667 MT/s front side bus, and the thermal envelope is 135 W. The package is a 604-pin part for Socket 604 boards.

Cache is the reason this SKU existed. It carries 1 MB of on-die L2 cache plus 8 MB of on-die L3 cache, all built on a 90 nm process. Intel's own Potomac datasheet describes the family as shipping with either 4 MB or 8 MB of L3, and the 8 MB option gave database and consolidation servers a much larger pool of fast cache than the plain 1 MB L2 Cranford parts. TechPowerUp lists this 8 MB variant at 135 W with ECC memory support and a locked multiplier.

A naming trap surrounds this model, so it deserves a plain explanation. Wikipedia documents sSpec SL8ED at 2.83 GHz with 1 MB of L2 plus 4 MB of L3 at 129 W, and TechPowerUp carries the same 4 MB and 129 W pairing on a separate page. This page covers the other variant: 8 MB of L3 at 135 W, as listed by TechPowerUp. No opened source ties a confirmed sSpec number to the 8 MB variant, so none is stated here. Buyers matching a physical chip should check the sSpec printed on the package against the board support list rather than trusting the model name alone.

Socket and motherboard compatibility

The chip fits Socket 604, the 604-pin mPGA604 zero insertion force socket used by Intel NetBurst server boards. As an MP part it belongs in multiprocessor boards that scale to four sockets and beyond, which is the topology Wikipedia records for Potomac and which Intel's datasheet confirms with support for four processors and beyond. That separates it from DP parts, which are limited to boards with up to two sockets.

Board and BIOS qualification decide whether a given chassis accepts it. The board must list Potomac support, and its BIOS must carry the microcode for the installed stepping. Power delivery must be rated for a 135 W part, since some Socket 604 boards were qualified only for lower envelopes. The Socket vs chipset: what decides whether a CPU works guide explains how socket, chipset generation, and BIOS revision interact on server boards.

A used buyer has a short checklist. Confirm the socket is 604 and not 603, confirm the board vendor lists the 2.83 GHz Potomac explicitly, and confirm the chassis airflow path matches a 135 W multiprocessor population. Memory and slot behavior come from the board chipset, so the board manual is the authority there.

Memory, PCIe and cooling

Memory reaches the processor through the server board, and TechPowerUp records ECC support with a dual-channel board memory bus for this SKU. The exact memory type, speed, and capacity ceiling depend on the board and its chipset, so the server maker memory list governs population rules, slot order, and whether single or dual rank modules are required. Intel's datasheet notes 40-bit addressing on these MP parts, but usable capacity is set by the board design.

Expansion also lives on the board. A 667 MT/s front side bus ties the CPU to the server chipset, and PCIe or PCI-X slots hang off that chipset rather than the processor. There is no integrated graphics, so remote management or a basic board GPU handles console output. Throughput planning should start from the bus speed and the chipset block diagram, not from the CPU alone.

Cooling is a vendor affair at this power level. A 135 W multiprocessor population needs the server maker heatsink specified for the exact chassis, with the directed airflow that rack and pedestal boards assume. No retail tower cooler program applies here. Replacement thermal parts should be ordered for the exact board and chassis combination, and the heatsink must be rated for continuous operation at the full 135 W envelope.

Upgrade paths

Inside Socket 604 the natural step up is the Intel Xeon MP 3.00 at 3.0 GHz with 8 MB of L3, which keeps the same bus and socket while raising clocks. The later dual-core Paxville MP parts such as the Intel Xeon MP 7040 Dual-Core and the Intel Xeon MP 7041 Dual-Core add a second core per socket on boards whose BIOS lists them. The 65 nm Tulsa generation, for example the Intel Xeon 7140M, is the last same-socket family for these MP boards where the board vendor qualifies it.

Each of those moves needs the same checks as the original install: BIOS microcode for the new stepping, power delivery rated for the new TDP, and heatsinks matched to the chassis. Moving past Socket 604 entirely means a new board, new memory, and a new chassis airflow plan, since later Xeon generations use different sockets and chipsets.