Intel Xeon Bronze 3408U socket: LGA 4677
The Intel Xeon Bronze 3408U uses LGA 4677, the 4677-contact LGA socket for Sapphire Rapids server processors. The 8-core single socket chip at 125 W needs a server board with DDR5 memory.
- Socket
- LGA 4677
- Launched
- January 2023
- Cores and threads
- 8 and 8
- Base power
- 125 W
- Codename
- Sapphire Rapids
- Segment
- Server
- Family
- Intel Xeon Bronze
- Clocks
- 1.8 / 1.9 GHz
Intel Xeon Bronze 3408U specifications
| Cores | 8 (no Hyper-Threading) |
|---|---|
| Threads | 8 |
| Core architecture | Golden Cove (Sapphire Rapids) |
| Clocks | 1.8 GHz base, up to 1.9 GHz turbo |
| Cache | 22.5 MB Intel Smart Cache (L3) |
| Processor base power (TDP) | 125 W |
| Manufacturing process | Intel 7 |
| Memory support | DDR5 to 4800 MT/s, 8 channels |
| PCI Express | 80 PCIe Gen5 lanes with Flex Bus and CXL per CPU |
| UPI links | 0 (single socket only) |
| Multiplier | Locked |
| Package | LGA 4677 |
| Cooler in the box | None (server heatsink required) |
| Launch price | $498.00 to $508.00 Intel recommended customer price |
Motherboard and chipset compatibility
Intel Xeon Bronze 3408U needs a motherboard with a LGA 4677 socket. The table shows which chipset series accept it.
| Series | Chipsets | Support |
|---|---|---|
| W790 workstation | W790 | 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 4677.
LGA 4677 at a glance
| Type | LGA, 4,677 contacts |
|---|---|
| Package size | 77.5 × 56.5 mm |
| Introduced | 2023 |
| Memory | DDR5-4800 Registered DIMMs with ECC, 8 channels up to 4 TB on W-3500 and W-3400, 4 channels on W-2500 and W-2400 |
| Cooler mounting holes | Board specific (workstation heatsink) |
What the Xeon Bronze 3408U is
The Xeon Bronze 3408U is the 8-core single socket entry of Sapphire Rapids server processors for LGA 4677 boards from the first quarter of 2023. Eight Golden Cove cores without hyperthreading give 8 cores and 8 threads, with base at 1.8 GHz and up to 1.9 GHz turbo. The package carries 22.5 MB of Smart Cache. The 125 W envelope suits single-socket edge servers with server lifecycle. No UPI links means no dual socket pairing.
No Hyper-Threading keeps threading simple for fixed-function appliances that license by thread. Eight channels of DDR5 feed 8 cores for storage and gateway duty. Eighty Gen5 lanes with Flex Bus and CXL serve NICs and NVMe in one chassis.
Entry server buyers land here for the cheapest Sapphire Rapids node at 125 W. Eight threads cover dedicated appliances, while Silver parts add threads for busier hosts. Server boards need C741 class chipsets with the Bronze SKU on the CPU list, not W790 workstation boards. The Socket vs chipset: what decides whether a CPU works guide covers server board choice.
Socket and motherboard compatibility
The 3408U fits LGA 4677 on single socket server boards with LGA 4677 retention and server power delivery. Dual socket operation is impossible with zero UPI links, so the board list must name the U suffix part. W790 workstation boards target W-series chips instead, so server C741 class boards are the correct home.
Server chipset choice decides management and IO breadth rather than CPU fit. Single-socket operation only keeps platform cost down against dual socket Xeon Gold racks.
Memory, PCIe and cooling
DDR5 to 4800 MT/s in 8 channels feeds 8 cores for storage duty. Population with matched DIMMs holds rated speed. Two DIMMs per channel remain possible where boards wire them.
Eighty Gen5 lanes with Flex Bus and CXL per CPU wire NICs, accelerators and NVMe. Cooling is a 125 W server heatsink with front-to-back airflow.
Upgrade paths
On LGA 4677 single socket boards the upward moves are Silver and Gold parts where thread counts grow, without adding sockets. Memory growth and NIC additions often help more than cores.
Outside single-socket Bronze, dual socket Silver and Gold on LGA 4677 add sockets for larger fabrics. Most 3408U owners add storage first.
Frequently asked questions
What socket does the Xeon Bronze 3408U use?
LGA 4677 on single socket server boards. It does not support dual socket operation.
Does the 3408U have Hyper-Threading?
No. Eight cores give 8 threads at 1.8 GHz base and up to 1.9 GHz turbo.
What is the launch price of the 3408U?
$498.00 to $508.00 Intel recommended customer price.
Can the 3408U run in dual socket?
No. Zero UPI links restrict it to single socket only.
Sources and verification
Facts last checked against these sources on . Page last edited on .