AMD Opteron 146 HE socket: Socket 940

What the Opteron 146 HE is

The AMD Opteron 146 HE is a 2 GHz high-efficiency single-core server processor from February 2004. It runs one K8 core at 2 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 55 W in a Socket 940 package with part number OSK146CMP5AT in the CG stepping.

HE marks a high-efficiency bin at 1.30 V, below the 1.50 V of standard SledgeHammer parts at nearby clocks. Standard Opteron 146 at 2 GHz carries an 89 W rating, so the HE bin saves 34 W at the same frequency and cache. AMD sold the HE bin at 733 dollars for dense single-socket racks where power caps node count. The chip supports MMX, SSE, SSE2, Enhanced 3DNow, NX bit and AMD64 with registered PC3200 DDR and an 800 MHz HyperTransport link.

Efficiency bins matter in racks with fixed power budgets. A row of 146 HE parts at 55 W each fits more servers per circuit than standard 89 W parts, with lower fan speeds and smaller heatsinks. That density premium explains the higher launch price against standard bins with identical clocks.

Socket and motherboard compatibility

The 146 HE fits Socket 940 single-processor dense servers with registered DDR memory and a BIOS that lists HE SledgeHammer parts. It needs a board qualified for 55 W HE operation at 1.30 V, not just any Socket 940 board with standard power tables. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.

Dense single-socket chassis are the natural match. Boards listing HE parts adjust voltage and fan curves for 55 W operation. Standard power boards may seat the chip yet run cooling too aggressively without HE BIOS support. Dual-processor needs 200 series HE parts such as the 246 HE instead.

Memory, PCIe and cooling

Memory is registered DDR with ECC through the on-chip controller, reaching PC3200. Only registered modules boot, with ECC for server reliability.

HyperTransport at 800 MHz links the CPU 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 55 W server heatsinks with directed rack airflow. Lower power allows denser packing, but blocked vents still raise temperatures quickly. DDR2 needs Socket F.

Upgrade paths

On Socket 940 the HE steps include higher single-socket HE bins where listed, while standard power 148 at 2.2 GHz offers more clocks at higher power. Venus 100 series HE successors on 90 nm add SSE3 with similar power goals. Beyond Socket 940 a move to Socket F needs DDR2 boards with Santa Rosa HE parts. The 146 HE lifts with the lever, so swaps need no solder work.