Intel Xeon MP 3.00 socket: Socket 604

What the Xeon MP 3.00 is

The Intel Xeon MP 3.00 is a single-core multiprocessor server processor from March 2005. One NetBurst core runs at 3.0 GHz through an 18x multiplier on a 667 MT/s front side bus, and Hyper-Threading presents that core as 2 threads to the operating system. The sSpec for the 8 MB part is SL8EW and the order number is RK80546KF0808M, both recorded by Wikipedia and confirmed by parts listings. The build here is 90 nm in a 604-pin package for Socket 604.

Cache defines this SKU. It carries 1 MB of on-die L2 plus 8 MB of on-die L3, the largest L3 option Intel offered in the Potomac family. The Retro Web hardware database confirms the Potomac core with 1 MB of L2, 8 MB of shared L3, a 667 MHz bus, and an 18x multiplier at 3000 MHz for RK80546KF0808M. That cache pool is what separated Potomac from the L2-only Cranford MP parts sold beside it, and it is why these chips were aimed at large database and consolidation servers rather than dual-socket departmental boxes.

Power needs a note because the sources do not speak with one voice. TechPowerUp lists the Potomac 3.00 GHz part at 135 W, which is the value used on this page. The Retro Web database records 130 W for RK80546KF0808M, while two parts vendors list the same order number at 129 W. Wikipedia leaves the TDP cell for the SL8EW row blank. Since the per-SKU database value and the wider family data point to 135 W, that figure is used here, and the disagreement is stated openly so a buyer can confirm the envelope against the board support list.

Socket and motherboard compatibility

The processor fits Socket 604, the 604-pin mPGA604 zero insertion force socket. As an MP chip it targets multiprocessor boards that scale to four sockets and beyond, the topology Wikipedia assigns to the whole Potomac family and that Intel's MP datasheet backs with support for four processors and beyond. Dual-socket DP boards are a different population with different qualification, even where the socket looks the same.

Qualification is board specific. The server board must list the SL8EW Potomac explicitly, the BIOS must include its microcode, and the voltage regulation must be rated for a 135 W part. Some Socket 604 boards were qualified only for lower power envelopes, so a socket match alone does not guarantee support. The Socket vs chipset: what decides whether a CPU works guide covers how socket, chipset generation, and BIOS revision combine on server platforms.

When reusing a chassis, check three things before ordering: the board CPU list names RK80546KF0808M or SL8EW, the installed BIOS revision covers it, and the airflow path matches a fully populated 135 W multiprocessor layout. Memory behavior, slot layout, and console output all come from the board design.

Memory, PCIe and cooling

Memory travels through the server board, and TechPowerUp records ECC support for this SKU. Rank rules, slot population order, and the maximum usable capacity are set by the board and its chipset, so the server maker memory list is the binding document. Parts listings describe these boards with registered server memory, but the exact type and speed for a given chassis should be read from the board manual rather than assumed from the CPU.

A 667 MT/s front side bus connects the processor to the server chipset, and all expansion slots hang off that chipset. There is no integrated graphics on the die, so console duties fall to board level graphics or remote management hardware. Anyone sizing I/O for one of these systems should work from the chipset diagram and the bus speed, since the CPU contributes no lanes of its own.

Thermal planning centers on the 135 W envelope and the disagreement around it. The vendor heatsink specified for the exact chassis is the correct part, and it should be rated for continuous full load operation in a multiprocessor population with directed airflow. Given that some listings show 129 W or 130 W for the same order number, keeping the stronger 135 W cooling assumption costs nothing and protects against the warmest documented case.

Upgrade paths

Within Socket 604 the path forward from a 3.0 GHz Potomac is lateral or generational rather than a clock increase, since this SKU already sits near the top of the Potomac clock range. The 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 family, for example the Intel Xeon 7140M, is a later same-socket option where the board vendor qualifies it.

Every one of those swaps repeats the same qualification loop: board CPU list, BIOS revision, power envelope, and chassis cooling. A move past Socket 604 to any modern Xeon generation requires a new board, new memory, and a new chassis thermal plan.