AMD Opteron 4256 EE socket: Socket C32

What the Opteron 4256 EE is

AMD Opteron 4256 EE is an 8 core Valencia server part that AMD released in November 2011 for dense two socket servers. It uses the Bulldozer core design on a 32 nm process, running at 1.6 GHz base with Turbo Core to 2.8 GHz through a 1.9 GHz all core step. The chip holds four Bulldozer modules with eight threads, 8 MB of L2 with 2 MB per module, and 8 MB of shared L3. Power is only 35 W. The EE suffix marks energy efficient tuning at 32 W ACP.

The cores have no Hyper-Threading, so threads equal cores at 8. Low base clocks with a tall turbo range suit bursty edge services that idle most of the time. The package integrates two HyperTransport 3.1 links and a dual channel ECC memory controller on die.

At 35 W the Opteron 4256 EE belongs to the lowest power group of the Valencia line. The clocks suit scale out racks with directed airflow. Boards are vendor qualified designs with ECC RDIMM slots. The How to find your CPU socket type guide shows how to confirm the socket before ordering parts.

Socket and motherboard compatibility

The Opteron 4256 EE fits Socket C32 in LGA form with 1,207 contacts. Socket C32 launched in June 2010 for Lisbon parts, so Valencia chips boot on C32 boards that list them, after a BIOS update. Check ECC RDIMM support per board. Boards are single and dual socket server designs from system vendors, qualified per model.

Power delivery at 35 W suits dense chassis with shared cooling and vendor heatsinks. Memory support decides more builds than power: the board must accept ECC RDIMMs. The CPU cooler compatibility by socket guide notes server sockets use board specific heatsinks.

Memory, PCIe and cooling

Memory support is DDR3 up to 1600 MT/s, two channels, ECC. ECC RDIMMs are the server choice, since they catch single bit errors in long running guests. Balance DIMMs across channels and sockets for NUMA fairness.

PCI Express comes from the chipset, not from the Opteron die. HyperTransport links tie the sockets together and feed the chipset, while PCIe Gen 2 slots hang off the board.

Cooling uses dense server heatsinks with directed airflow. The 35 W envelope sizes the heatsink and fan wall.

Upgrade paths

Within Socket C32 the Opteron 4256 EE sits in the low power group for dense nodes. A same socket move adds clocks or cores where the board BIOS lists the target, including Seoul Piledriver parts on updated boards.

A real upgrade means a new platform. AMD moved servers to EPYC on SP3 and beyond with DDR4 memory and many more cores. That move needs a new board, new memory and often a new chassis. Keep the node for secondary duty or retire it whole.