Intel Pentium III Xeon 733 2.8V socket: Slot 2

What the Pentium III Xeon 733 2.8V is

The Intel Pentium III Xeon 733 2.8V is a 733 MHz single-core server processor from October 1999. It runs one P6 Cascades core at 733 MHz with no Hyper-Threading, so 1 core gives 1 thread. Cache is 256 KB of full-speed L2 with 32 KB of L1 on a 180 nm process with 28 million transistors. Power is rated at 23.3 W in a Slot 2 SECC cartridge on a 133 MT/s front side bus with a 5.5x multiplier on the 2.8 V regulator path.

A half-ratio step over the 667 at a small power cost makes the 733 a steady performance pick, which is why it headed dual performance servers in late 1999. Intel launched the Xeon 733 on October 25, 1999 at $826. The chip supports MMX, SSE and two-way SMP.

Upper entry clocks with a fast bus suit Slot 2 performance boards. The 5.5x half-ratio needs an exact BIOS string. That is why the 733 2.8V shipped in performance workgroup boxes.

Socket and motherboard compatibility

The 733 2.8V fits Slot 2 performance servers with 2.8 V regulation. It needs a 330-lead SC330 board with a 133 MT/s bus and a BIOS that lists the 2.8 V 733 string. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

Performance rack servers are the natural match. Boards listing the string accept cartridges with 23.3 W heatsinks.

Memory, PCIe and cooling

Memory is registered SDRAM through the server chipset, matched to the board sockets. The cartridge has no memory controller. Performance boards commonly run ECC pairs.

A 133 MT/s front side bus ties each cartridge to the chipset, while PCI hangs off the chipset. No PCIe lanes originate on the cartridge. Cooling uses SECC heatsinks on the retention cage.

Upgrade paths

On the same slot, a move to a Pentium III Xeon 733 5V-12V such as Intel Pentium III Xeon 733 5V-12V keeps clocks and cache while changing regulator path. A Xeon 667 2.8V such as Intel Pentium III Xeon 667 2.8V drops clocks at lower power.

A move to Tanner Xeon drops to 100 MT/s paths. The Slot 2 page lists the range.