IDT WinChip 2A-300 socket: Super Socket 7

What the WinChip 2A-300 is

The IDT WinChip 2A-300 is a 250 MHz single-core desktop processor from March 1999. It runs one Centaur WinChip 2A core at 250 MHz with no turbo, so 1 core gives 1 thread. Cache is 64 KB of L1 with no on-die L2 on a 0.25 micron process. Power is rated at 16 W in a Super Socket 7 CPGA package on a 100 MHz front side bus with a 2.5x multiplier.

The 2A revision adds 100 MHz bus operation with fractional multipliers over plain WinChip 2 parts, which is why the 2A-300 at 250 MHz needs a Super Socket 7 board while older strings run on plain Socket 7. IDT sold 2A parts from March 1999. The chip supports MMX and 3DNow.

A 250 MHz clock on a full 100 MHz bus suits late Super Socket 7 towers with PC100 memory. The 2.5x fractional ratio needs an exact BIOS setting. That is why the 2A-300 shipped in late budget towers.

Socket and motherboard compatibility

The 2A-300 fits Super Socket 7 late desktops with WinChip 2A support. It needs a 321-pin board with a 100 MHz bus path and a BIOS that lists WinChip 2A parts. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

Late PC100 towers are the natural match. Boards listing WinChip 2A-300 accept the chip with a 16 W cooler. Plain Socket 7 boards with no 100 MHz tables cannot feed the ratio.

Memory, PCIe and cooling

Memory is SDRAM through the board chipset, matched to the board sockets. The CPU has no memory controller. Late boards commonly run 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 exist. Cooling uses the socket lug clip with a 16 W cooler.

Upgrade paths

On the same socket, a WinChip 2-250 such as IDT WinChip 2-250 drops to 233 MHz actual at 10.9 W on an 83 MHz bus. An AMD K6-2 on the same support list adds 3DNow performance at higher clocks.

A move to VIA C3 needs a Socket 370 board. The Super Socket 7 page lists the range for planning.