AMD Opteron 240 socket: Socket 940

What the Opteron 240 is

The AMD Opteron 240 is a 1.4 GHz single-core server processor from May 2004. It runs one K8 core at 1.4 GHz with no turbo, so 1 core gives 1 thread. Cache is 1 MB of L2 on a 130 nm process. Power is rated at 82 W in a Socket 940 package with part number OSA240CEP5AU in the CG stepping.

The 240 opens the 200 series SledgeHammer line for two-processor servers, where the leading 2 marks dual-processor use. It shares its 1.4 GHz and 1 MB rating with the single-processor 140, yet the 200 series package enables coherent links to a second socket. The part uses a 200 MHz system clock with a 7x multiplier at 1.50 V and an 800 MHz HyperTransport link. AMD listed the CG revision at 198 dollars in May 2004. The chip supports MMX, SSE, SSE2, Enhanced 3DNow, NX bit and AMD64 with registered PC3200 DDR on CG parts.

Dual-processor scope decides the board. The 240 suits two-socket Socket 940 servers with registered DDR slots and multiprocessor power delivery, not single-socket 100 series boards with uniprocessor-only BIOS tables. That second socket doubles core count per chassis at the same per core clocks, which suited departmental servers and small clusters.

Socket and motherboard compatibility

The Opteron 240 fits Socket 940 dual-processor server boards with registered DDR memory and a BIOS that lists SledgeHammer 200 series parts. It needs a two-socket board with multiprocessor power delivery, not a single-socket 100 series board. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

Two-socket entry servers are the natural match. Boards listing the 240 normally accept higher 200 series parts such as the 242 at 1.6 GHz and the 244 at 1.8 GHz with the same 82 W cooling. Single-processor 140 parts at the same clocks do not enable the second socket, even though the package looks similar. Forcing the wrong series can leave the second socket dark.

Memory, PCIe and cooling

Memory is registered DDR with ECC through the on-chip controller. CG parts reach PC3200, early parts reach PC2700. Each CPU carries its own memory channels, so two-socket boards populate DIMMs per socket for balanced bandwidth.

HyperTransport at 800 MHz links the two CPUs to each other and to the server chipset, while PCIe or PCI-X slots hang off the chipset. No PCIe lanes originate on the die. Cooling uses vendor qualified 82 W server heatsinks per socket with front to back rack airflow. Both sockets need matched heatsinks and paste for stable operation. DDR2 needs Socket F.

Upgrade paths

On Socket 940 the steps are the Opteron 242 at 1.6 GHz and the 244 at 1.8 GHz with the same cache and power for two-socket boards. The 240 EE at 30 W suits dense dual-processor racks trading clocks for power. Troy 200 series successors on 90 nm add SSE3 where listed. Beyond Socket 940 a move to Socket F needs DDR2 boards. The 240 lifts with the lever, so swaps need no solder work.