AMD Opteron 856 socket: Socket 940
The AMD Opteron 856 uses the Socket 940 socket. It is a 92.6 W single-core Athens server part at 3 GHz with 1 MB of L2 cache for eight-processor racks.
- Socket
- Socket 940
- Launched
- April 2006
- Cores and threads
- 1 and 1
- Default TDP
- 92 W
- Codename
- Athens
- Segment
- Server
- Family
- AMD Opteron
- Clocks
- 3.0 GHz
AMD Opteron 856 specifications
| Cores | 1 |
|---|---|
| Threads | 1 |
| Core architecture | Athens cores on 90 nm |
| Clocks | 3 GHz (no turbo) |
| Cache | 1 MB L2 |
| Default TDP | 92.6 W |
| Manufacturing process | 90 nm |
| Memory support | Registered DDR, through the on-chip controller |
| PCI Express | PCIe from the board chipset |
| Integrated graphics | None |
| Multiplier | Locked |
| Package | Socket 940 (940-pin OPGA) |
Motherboard compatibility
AMD Opteron 856 needs a motherboard with a Socket 940 socket. Chipset by chipset data for this codename is not recorded yet. See the Socket 940 chipset list and the board maker's CPU support list.
Socket 940 at a glance
| Type | PGA, 940 contacts |
|---|---|
| Package size | 40 × 40 mm |
| Introduced | 2003 |
| Memory | Registered DDR, through the on-chip controller |
| Cooler mounting holes | Board specific (server heatsink) |
What the Opteron 856 is
The AMD Opteron 856 is a 3 GHz single-core server processor from April 2006. It runs one K8 core at 3 GHz with no turbo, so 1 core gives 1 thread. Cache is 1 MB of L2 on a 90 nm process. Power is rated at 92.6 W on Socket 940.
The 856 topped the Athens 800 series on a 1000 MT/s HyperTransport link. It exists because eight-processor servers wanted the fastest Athens single core with the full 1 MB cache for per-core licensed workloads.
Socket and motherboard compatibility
The 856 fits Socket 940 eight-processor server boards with a BIOS that lists Athens single cores. It suits multi-socket racks qualified for 92.6 W parts. Check the server maker CPU list for the exact board and stepping. The Socket vs chipset: what decides whether a CPU works guide covers pairing rules.
Memory, PCIe and cooling
Memory is registered DDR through the on-chip controller.
HyperTransport at 1000 MT/s links the CPU to the chipset and other sockets. PCIe slots hang off the chipset.
Cooling uses vendor qualified server heatsinks for the 92.6 W envelope with directed airflow.
Upgrade paths
On Socket 940 the upgrade is dual-core Italy or Egypt parts such as the 2.8 GHz 890 where the board lists them, or the 852 at 2.6 GHz for a lower cost single core. Beyond Socket 940 a move to Socket F needs new boards and DDR2 memory.
Frequently asked questions
What socket does the Opteron 856 use?
Socket 940, in eight-processor server boards with Athens support.
How many cores does the Opteron 856 have?
One core and 1 thread at 3 GHz with 1 MB of L2 cache.
What memory works with the Opteron 856?
Registered DDR through the on-chip controller.
Sources and verification
Facts last checked against these sources on . Page last edited on .