Intel Pentium 4 1.3 socket: Socket 423

What the Pentium 4 1.3 is

The Intel Pentium 4 1.3 is a 1300 MHz single-core desktop processor from January 2001. It runs one NetBurst Willamette core at 1300 MHz with no Hyper-Threading, so 1 core gives 1 thread. Cache is 256 KB of Advanced Transfer Cache with 8 KB of L1 data plus trace cache on a 180 nm process with 42 million transistors. Power is rated near 52 W in a Socket 423 organic PGA package with part numbers SL4SF and SL5GC on a 400 MT/s front side bus with a 13x multiplier at up to 1.75 V.

The first NetBurst desktop core trades instructions per clock for clock speed over P6 parts, which is why the 1.3 at 1300 MHz needs RDRAM bandwidth to show its pace against Pentium III 1000 parts. Intel launched the 1.3 on January 3, 2001 with the 1.4 and 1.5 Socket 423 parts. The chip supports MMX, SSE and SSE2.

Early clocks with a quad-pumped bus suit first Socket 423 towers with RDRAM and AGP graphics. The 52 W envelope needs the tall Socket 423 cooler with ducted air. That is why the 1.3 shipped in launch Pentium 4 systems with Rambus memory.

Socket and motherboard compatibility

The 1.3 fits Socket 423 first-generation desktops with Willamette support. It needs a 423-pin board with a 400 MT/s bus and a BIOS that lists Pentium 4 1.3. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

RDRAM towers with i850 paths are the natural match. Boards listing Pentium 4 1.3 accept the chip with a 52 W Socket 423 cooler. Socket 478 boards cannot accept the 423-pin package under any setting.

Memory, PCIe and cooling

Memory is RDRAM and SDRAM through the board chipset, matched to the board slots. The CPU has no memory controller, so the chipset sets the type. Launch i850 boards commonly run PC800 RDRAM pairs for 400 MT/s parts.

A 400 MT/s front side bus ties the CPU to the chipset on a 100 MHz quad-pumped clock, while AGP and PCI hang off the chipset. No PCIe lanes originate on the die. Cooling uses the Socket 423 bracket with a cooler rated for 52 W.

Upgrade paths

On the same socket, a move to a Pentium 4 1.5 on Socket 423 keeps the board and memory when the support list names it, though this block covers the Socket 478 1.5 such as Intel Pentium 4 1.5 on a new board. Within Socket 423, faster Willamette strings share the 400 MT/s bus when power tables allow. A Pentium III 1400 such as Intel Pentium III 1400 is a different socket and needs a Socket 370 board.

A move to Socket 478 Willamette needs a new 478-pin board with its own bracket. The Socket 423 page lists the short Willamette 423 range, with Socket 478 as successor. Note: the queue row lists Socket 478 for the 1.3; this page uses the verified Socket 423 package.