Intel Xeon Platinum 8256 socket: LGA 3647
The Intel Xeon Platinum 8256 uses the LGA 3647 socket on C620 series server boards. It is a 4 core chip with the highest clocks in the Platinum line for licensed databases.
- Socket
- LGA 3647
- Launched
- April 2, 2019
- Cores and threads
- 4 and 8
- Base power
- 105 W
- Codename
- Cascade Lake-SP
- Segment
- Server
- Family
- Intel Xeon Platinum
- Clocks
- 3.8 / 3.9 GHz
Intel Xeon Platinum 8256 specifications
| Cores | 4 |
|---|---|
| Threads | 8 |
| Core architecture | Cascade Lake-SP |
| Clocks | 3.8 GHz base, up to 3.9 GHz boost |
| Cache | 16.5 MB L3 (shared) |
| Processor base power (TDP) | 105 W |
| Manufacturing process | 14 nm |
| Memory support | DDR4-2933, six channels, up to 1 TB |
| PCI Express | PCIe 3.0, 48 lanes from the CPU |
| UPI links | 3 links at 10.4 GT/s |
| Integrated graphics | None |
| Multiplier | Locked |
| ECC memory | Yes |
| Package | FCLGA3647 (76.0 by 56.5 mm) |
Motherboard and chipset compatibility
Intel Xeon Platinum 8256 needs a motherboard with a LGA 3647 socket. The table shows which chipset series accept it.
| Series | Chipsets | Support |
|---|---|---|
| C620 series | C621 | Works out of the box |
Board makers publish a CPU support list for every model. Check it for your exact board before buying. Chipset details for LGA 3647.
LGA 3647 at a glance
| Type | LGA, 3,647 contacts |
|---|---|
| Package size | 76.0 × 56.5 mm |
| Introduced | 2016 |
| Memory | DDR4-2933 ECC, six channels, up to 2 TB |
| Cooler mounting holes | Board specific (narrow and square ILM heatsinks) |
What the Xeon Platinum 8256 is
The Xeon Platinum 8256 is a four core, eight thread server processor with a 3.8 GHz base and up to 3.9 GHz boost. It carries 16.5 MB of shared L3 cache and a 105 W TDP on the 14 nm process. Intel launched it on April 2, 2019 with the 2nd Gen Xeon Scalable family.
It trades core count for clocks: the highest base in the Platinum line for per core licensed databases that charge by the core. Four fast cores beat twenty slow ones where licenses dominate the budget. The multiplier is locked.
There is no integrated graphics. ECC memory and Optane persistent memory are supported. Pricing is omitted here because ARK and launch lists disagree between $7007 and $8030.
Socket and motherboard compatibility
The 8256 fits LGA 3647 on server boards with the C620 series chipsets. Boards need a BIOS with 2nd Gen Scalable support and the exact SKU on the vendor list. Few boards are validated for such a niche SKU, so the vendor list decides.
C620 series boards carry six channel DDR4 and 48 PCIe 3.0 lanes per CPU. Rack chassis need front to back airflow with vendor qualified heatsinks. Check the board memory QVL for DIMM combinations.
The chip ships tray only with no cooler. The Intel Xeon W-3175X shares the socket on workstation boards, while server racks use Scalable parts like this one.
Memory, PCIe and cooling
Memory support is DDR4-2933 in six channels up to 1 TB, with ECC and Optane persistent memory. Database nodes love both speed and capacity, so validated kits at rated speed beat faster desktop kits. Six channels feed four cores with room to spare.
PCI Express arrives as version 3.0 with 48 lanes from the CPU for NVMe and network cards. Three UPI links at 10.4 GT/s connect sockets in multi node racks. Cooling uses vendor 105 W server heatsinks with directed airflow.
Upgrade paths
On the same socket the move sideways is a higher core part where thread density matters, keeping board and DDR4. The 8256 keeps its place wherever per core licenses make four fast cores cheaper than sixteen average ones.
Moving past LGA 3647 means a new board on a current server platform. Database owners usually add memory before replacing processors.
Frequently asked questions
What socket does the Xeon Platinum 8256 use?
It uses LGA 3647 on C620 series server boards with a BIOS that lists 2nd Gen Xeon Scalable parts.
How many cores does the 8256 have?
Four cores with Hyper-Threading give eight threads at 3.8 GHz base with up to 3.9 GHz boost, with 16.5 MB of cache at 105 W.
Why buy a 4 core Platinum?
Per core licensed databases that charge by the core. Four fast cores cost fewer licenses than sixteen slower ones with similar single thread speed.
What memory does the 8256 support?
DDR4-2933 in six channels up to 1 TB, with ECC and Optane persistent memory support.
How many PCIe lanes and UPI links does the 8256 have?
48 PCIe 3.0 lanes from the CPU plus 3 UPI links at 10.4 GT/s for multi socket racks.
Sources and verification
- Intel Xeon Platinum 8256 specifications (Intel)
- Intel Xeon Platinum 8256 specs (TechPowerUp CPU database)
Facts last checked against these sources on . Page last edited on .