Intel Xeon 3.0 socket: Socket 604

What the Xeon 3.0 is

The Intel Xeon 3.0 is a single-core dual-socket server processor that arrived in February 2005. It runs one NetBurst core at 3.0 GHz through a 15x multiplier on an 800 MT/s front side bus. Hyper-Threading is supported across the Irwindale family, so the core presents 2 threads. The tray sSpec is SL8ZQ with order number RK80546KG0802MM, while boxed E-suffix parts shipped under sSpecs such as SL8P6. The process is 90 nm and the socket is 604.

Cache is the Irwindale signature. This SKU carries 2 MB of on-die L2, twice the 1 MB of the Nocona generation it replaced, and the CPU-World sSpec page for SL8P6 confirms the 2 MB size with an 800 MHz bus on Socket 604. That same page records 1 core with 2 logical processors, which pins the thread count at 2 without inference. There is no L3 cache on this die; the large L2 is the whole cache story.

Power deserves attention because aggregate lists sometimes print 135 W for these bins. The per-SKU evidence says 110 W: CPU-World lists 110 W for the 3.0 GHz Irwindale sSpec, and Wikipedia shows 110 W for the adjacent 2.8 GHz Irwindale row while leaving the other TDP cells in the table blank. This page uses the verified 110 W figure. Board planners should still confirm the envelope against the server maker CPU list, since chassis cooling is ordered per board rather than per model name.

Socket and motherboard compatibility

The chip fits Socket 604, the 604-pin mPGA604 zero insertion force socket shared by the NetBurst Xeon DP and MP lines. As a DP part it belongs in boards with up to two sockets, the dual-processor topology Wikipedia records for Irwindale and that Intel's 2 MB Xeon datasheet confirms with scalability to two processors. Multiprocessor boards with four or more sockets are MP territory and follow different qualification.

A socket match is only the start. The board must list the 3.0 GHz Irwindale by sSpec, the BIOS must include its microcode, and the power design must cover a 110 W part. Tray and boxed suffixes can matter here: no-suffix parts are tray and E-suffix parts are boxed, and some vendors qualify them on separate lines of the CPU list. The Socket vs chipset: what decides whether a CPU works guide explains the interaction of socket, chipset generation, and BIOS revision.

Population checks for a used system are simple. Verify the board CPU list names SL8ZQ or the installed sSpec, verify the BIOS revision covers it, and verify the chassis provides the airflow path the board manual assumes for a dual 110 W population.

Memory, PCIe and cooling

Memory and expansion both live on the server board for this generation. No opened source states the board memory type for this exact SKU, so this page makes no memory type claim and the board manual governs instead. Type, speed, rank rules, and the maximum usable capacity all come from the server maker memory list for the exact board, and Intel's datasheet notes these DP platforms address up to 64 GB through the board design.

The processor ties to the board chipset over an 800 MT/s front side bus, and every expansion slot hangs off that chipset. Lane counts and slot versions are board facts, not CPU facts, on this platform. Console output comes from board level graphics or remote management hardware.

Cooling follows the 110 W envelope with vendor parts. The heatsink must be the server maker part specified for the exact board and chassis, with the directed airflow that dual-socket rack and pedestal boards assume. When moving between Irwindale bins in the same chassis, keep the existing thermal parts only if they are rated for the new bin; the board manual is the authority.

Upgrade paths

The clock step inside the same family is the Intel Xeon 3.6 at 3.6 GHz, which keeps the 2 MB L2, the 800 MT/s bus, and the same socket on boards that list it. The intermediate bins, the Intel Xeon 3.2 and the Intel Xeon 3.4, give smaller steps where the board list and thermals favor them. Each swap needs a BIOS that covers the new sSpec and cooling rated for the verified 110 W envelope.

A larger change is the dual-core Paxville DP Intel Xeon 2.8, which doubles cores per socket on boards whose BIOS lists it. Past Socket 604 entirely, any newer Xeon generation needs a new board, new memory, and a new chassis thermal plan.