Intel Xeon Platinum 8276 socket: LGA 3647
The Intel Xeon Platinum 8276 uses the LGA 3647 socket on C620 series server boards. It is a 28 core Cascade Lake-SP chip at 165 W for dense virtualization racks.
- Socket
- LGA 3647
- Launched
- April 2, 2019
- Cores and threads
- 28 and 56
- Base power
- 165 W
- Codename
- Cascade Lake-SP
- Segment
- Server
- Family
- Intel Xeon Platinum
- Clocks
- 2.2 / 4.0 GHz
Intel Xeon Platinum 8276 specifications
| Cores | 28 |
|---|---|
| Threads | 56 |
| Core architecture | Cascade Lake-SP |
| Clocks | 2.2 GHz base, up to 4.0 GHz boost |
| Cache | 38.5 MB L3 (shared) |
| Processor base power (TDP) | 165 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 8276 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 8276 is
The Xeon Platinum 8276 is a twenty eight core, fifty six thread server processor with a 2.2 GHz base and up to 4.0 GHz boost. It carries 38.5 MB of shared L3 cache and a 165 W TDP on the 14 nm process. Intel launched it on April 2, 2019 with the 2nd Gen Xeon Scalable family.
Twenty eight cores cover dense virtualization hosts at a lower base clock than the 205 W bins. Three UPI links at 10.4 GT/s join up to eight sockets per rack topology. The multiplier is locked at 22 times the base clock.
There is no integrated graphics. ECC memory and Optane persistent memory are supported up to 1 TB. Pricing is omitted here because ARK and launch lists disagree between $8719 and $9981.
Socket and motherboard compatibility
The 8276 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. Dual socket boards are the common home for this density class.
C620 series boards carry six channel DDR4 and 48 PCIe 3.0 lanes per CPU for NVMe, network and accelerators. Rack chassis need front to back airflow with vendor qualified heatsinks. Check the board memory QVL for DIMM and Optane 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. Dense hosts reward capacity first, so 12 DIMMs of 64 GB with room for Optane suits virtualization. The M and L suffix siblings take the same board to 2 TB and 4.5 TB.
PCI Express arrives as version 3.0 with 48 lanes from the CPU. Three UPI links connect sockets in multi node racks. Cooling uses vendor 165 W server heatsinks with directed chassis airflow.
Upgrade paths
On the same socket the step up is a higher clock 28 core such as the Xeon Platinum 8280 where base speed matters, keeping board and DDR4. The 8276 keeps its place where 28 cores cover dense tenants at 165 W.
Moving past LGA 3647 means a new board on a current server platform. Rack owners usually add memory or network cards before replacing processors.
Frequently asked questions
What socket does the Xeon Platinum 8276 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 8276 have?
Twenty eight cores with Hyper-Threading give fifty six threads at 2.2 GHz base with up to 4.0 GHz boost, at 165 W.
What memory does the 8276 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 8276 have?
48 PCIe 3.0 lanes from the CPU plus 3 UPI links at 10.4 GT/s for multi socket racks.
How does the 8276 differ from the 8280?
The Xeon Platinum 8280 adds base clock in the same core count at 205 W. The 8276 covers dense tenants at lower power.
Sources and verification
- Intel Xeon Platinum 8276 specifications (Intel)
- Intel Xeon Platinum 8276 specs (TechPowerUp CPU database)
Facts last checked against these sources on . Page last edited on .