AMD Athlon 64 2800+ socket: Socket 754

What the Athlon 64 2800+ is

The AMD Athlon 64 2800+ is a 1800 MHz single-core desktop processor from April 2004. It runs one K8 core at 1800 MHz with no turbo, so 1 core gives 1 thread. Cache is 512 KB of L2 with 64 KB of L1 instruction and 64 KB of L1 data cache on a 130 nm process. Power is rated at 89 W in a Socket 754 package with part numbers ADA2800AEP4AP and ADA2800AEP4AR.

Clawhammer covers both C0 and CG steppings on Socket 754, with the 2800+ as the entry desktop rating in the April 2004 range. The part uses a 200 MHz system clock with a 9x multiplier at 1.50 V and an 800 MHz HyperTransport link. AMD sold it at 178 dollars, placing it below the 3000+ at 2000 MHz and the 3200+ at 2000 MHz with 1 MB. The chip supports MMX, SSE, SSE2, Enhanced 3DNow, NX bit and AMD64 with CoolnQuiet control.

Single channel memory separates Socket 754 from Socket 939. The 2800+ runs DDR through its on-chip controller in one channel with up to three unbuffered DIMMs, while Socket 939 adds a second channel for 6.4 GB/s. That is why Socket 754 remained the budget K8 desktop path after Socket 939 arrived for mid range and high end towers.

Socket and motherboard compatibility

The 2800+ fits Socket 754 desktops with DDR memory and a BIOS that lists Clawhammer parts. It needs a 754-pin board with single channel DDR slots, not a Socket 939 board with dual channel slots or a Socket A board with a front side bus. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

Budget DDR towers with AGP or early PCIe graphics are the natural match. Boards that list the 2800+ normally accept higher Clawhammer and Newcastle parts at similar power with the same cooler class. Late Venice support on Socket 754 is board specific, so the maker CPU list decides whether a 90 nm part boots. Forcing the chip into Socket 939 can damage pins.

Memory, PCIe and cooling

Memory is DDR through the on-chip controller in a single channel. Three unbuffered DIMMs or four registered DIMMs fit common boards, with speed set by the DDR modules and the controller. The 2800+ carries 512 KB of L2, half the 1 MB on higher Clawhammer 3200+ and 3400+ parts, which shows in cache sensitive tasks.

Expansion hangs off the board chipset. An 800 MHz HyperTransport link ties the CPU to the chipset, while AGP or PCIe slots provide graphics. No PCIe lanes originate on the die. Cooling uses two-hole heatsinks at 90 mm spacing with a cooler rated for 89 W. CoolnQuiet trims clocks and voltage at idle, which keeps office towers quiet with normal airflow.

Upgrade paths

On Socket 754 the direct steps are the Athlon 64 3000+ at 2000 MHz with 512 KB and the 3200+ at 2000 MHz with 1 MB, both sharing the Clawhammer base and 89 W envelope. Newcastle 2800+ parts offer the same rating on a newer stepping where listed. Beyond Socket 754 a move to Socket 939 needs a new board with dual channel DDR, with 3000+ and 3200+ Winchester and Venice parts as successors. A move to Socket AM2 needs DDR2 memory. The 2800+ lifts with the lever, so swaps need no solder work.