AMD Athlon 1200 (B) socket: Socket 462

What the Athlon 1200 (B) is

The AMD Athlon 1200 (B) is a 1200 MHz single-core desktop processor from October 2000. It runs one K7 Thunderbird B core at 1200 MHz with no turbo, so 1 core gives 1 thread. Cache is 256 KB of full-speed on-die L2 with 128 KB of L1 on a 180 nm process. Power is rated at 66 W in a Socket A ceramic PGA package on a 200 MT/s EV6 bus with a 12x multiplier.

A clean 12x integer ratio closes the 100 MHz B line at the top, which is why the 1200B suited buyers who want peak 200 MT/s clocks without a board move. AMD sold the 1200B in October 2000 with C-models. The chip supports MMX and Enhanced 3DNow.

Peak 100 MHz-bus clocks with a 66 W envelope suit late Socket A towers with strong airflow. The 12x ratio is the highest integer B multiplier. That is why the 1200B shipped in flagship 200 MT/s systems.

Socket and motherboard compatibility

The 1200 (B) fits Socket A flagship 200 MT/s desktops with Thunderbird-B support. It needs a 462-pin board with a 200 MT/s bus and a BIOS that lists Athlon 1200B. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

Flagship 200 MT/s towers are the natural match. Boards listing the 1200B accept the chip with a 66 W cooler. Weak early boards with small VRM stages may throttle.

Memory, PCIe and cooling

Memory is SDRAM through the board chipset, matched to the board sockets. The CPU has no memory controller. Flagship KT133A boards commonly run PC133 pairs.

A 200 MT/s EV6 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 462 lug clip with a 66 W cooler.

Upgrade paths

On the same socket, an Athlon 1200 (C) such as AMD Athlon 1200 (C) keeps the 1200 MHz mark while moving to a 133 MHz bus when the board supports it. The C swap lifts memory throughput at equal power. An Athlon 1100 drops 100 MHz at 60 W.

A move to Athlon XP needs 266 MT/s paths. The Socket 462 page lists the B and C range for planning.