Intel Pentium III 1200 socket: Socket 370

What the Pentium III 1200 is

The Intel Pentium III 1200 is a 1200 MHz single-core desktop processor from July 2001. It runs one P6 Tualatin core at 1200 MHz with no turbo, so 1 core gives 1 thread. Cache is 256 KB of full-speed L2 with 32 KB of L1 on a 130 nm process. Power is rated at 30 W in a Socket 370 FC-PGA2 package with part numbers SL5GN and SL5PM on a 133 MHz front side bus with a 9x multiplier at 1.475 V.

A clean 9x integer ratio on the 133 MHz bus gives the 1200 steady timing on late boards, which is why it became a common office pick between the 1133 and 1333. Intel placed the 1200 in July 2001 with the 1000, 1133 and 1266S parts. The chip supports MMX, SSE and hardware prefetch.

Mainstream clocks with a new process suit Socket 370 office towers with SDRAM and AGP graphics. The 30 W envelope keeps stock coolers small. That is why the 1200 shipped in corporate desktops with managed images.

Socket and motherboard compatibility

The 1200 fits Socket 370 mainstream desktops with Tualatin support. It needs a 370-pin FC-PGA2 Tualatin-ready board with a 133 MHz bus and a BIOS that lists Pentium III 1200. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

Corporate SDRAM towers are the natural match. Boards listing SL5GN accept the chip with a 30 W cooler. Older Coppermine-only boards with white sockets and no Tualatin microcode refuse it, so the blue-socket revision matters.

Memory, PCIe and cooling

Memory is PC100 and PC133 SDRAM through the board chipset, matched to the board DIMM sockets. The CPU has no memory controller, so the chipset sets the type and speed. Corporate 815E boards commonly run PC133 pairs for 1200 MHz parts.

A 133 MHz front side bus ties the CPU to the chipset, while AGP and PCI hang off the chipset. No PCIe lanes originate on the die. Cooling uses the Socket 370 lug clip on the FC-PGA2 spreader with a cooler rated for 30 W.

Upgrade paths

On the same socket, a move to a Pentium III 1333 such as Intel Pentium III 1333 keeps the board and memory when the support list names it. The 1333 adds 133 MHz at the same 30 W class, so the cooler carries over. A Pentium III 1133 such as Intel Pentium III 1133 drops 67 MHz at similar power.

A move to Celeron 1200 halves effective bus to 100 MHz with the same cache when budget matters. The Socket 370 page lists the Tualatin desktop range for planning.