AMD K6-2+ 550ACZ socket: Super Socket 7

What the K6-2+ 550ACZ is

The AMD K6-2+ 550ACZ is a 550 MHz single-core desktop processor from September 2000. It runs one K6 Sharptooth core at 550 MHz with no turbo, so 1 core gives 1 thread. Cache is 128 KB of full-speed on-chip L2 with 64 KB of L1 on a 180 nm process. Power is rated at 14 W in a Super Socket 7 CPGA package on a 100 MHz front side bus with a 5.5x multiplier.

The top fall clock of the ACZ line at a steady 14 W gives the 550ACZ the lead among desktop K6-2+ strings, which is why it headed late Super Socket 7 performance towers. AMD placed the 550ACZ in September 2000 with the 533ACZ. The chip supports MMX, 3DNow+ and PowerNow.

Peak K6-2+ clocks with a modest envelope suit late Super Socket 7 desktops with PC100 memory and AGP graphics. The 5.5x half-ratio needs an exact BIOS string. That is why the 550ACZ shipped in flagship Super 7 boxes.

Socket and motherboard compatibility

The 550ACZ fits Super Socket 7 performance desktops with late Sharptooth support. It needs a 321-pin board with a 100 MHz bus and a BIOS that lists K6-2+ 550ACZ. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

Performance SDRAM towers are the natural match. Boards listing K6-2+ 550ACZ accept the chip with a 14 W cooler.

Memory, PCIe and cooling

Memory is SDRAM through the board chipset, matched to the board sockets. The CPU has no memory controller. Performance boards commonly run tuned PC100 pairs.

A 100 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 lug clip with a 14 W cooler.

Upgrade paths

On the same socket, a K6-III+ 500ACZ such as AMD K6-III+ 500ACZ trades 50 MHz for double cache at 12 W when office software favors cache. A K6-2+ 533ACZ such as AMD K6-2+ 533ACZ drops 17 MHz at equal power. No faster K6-2+ ACZ string exists.

A move to Slot A Athlon needs a new board. The Super Socket 7 page closes the K6-2+ line for planning.