Intel Xeon W-11855M socket: BGA 1787
The Intel Xeon W-11855M uses the BGA 1787 package, a grid array that solders to the board. It is a 6-core Tiger Lake-H mobile workstation processor at 35 W with ECC memory, and the soldered chip cannot be replaced.
- Socket
- BGA 1787
- Launched
- May 2021
- Cores and threads
- 6 and 12
- Base power
- 35 W
- Codename
- Tiger Lake-H
- Segment
- Mobile (soldered)
- Family
- Intel Xeon W
- Clocks
- 3.2 / 4.9 GHz
Intel Xeon W-11855M specifications
| Cores | 6 |
|---|---|
| Threads | 12 |
| Core architecture | Willow Cove (Tiger Lake-H) |
| Clocks | 3.2 GHz base, up to 4.9 GHz turbo |
| Cache | 18 MB Intel Smart Cache (L3) |
| Processor base power (TDP) | 35 W |
| Manufacturing process | 10 nm SuperFin |
| Memory support | DDR4 up to 3200 MT/s ECC, two channels, up to 128 GB |
| PCI Express | PCIe Gen4 with 20 lanes from the CPU |
| Integrated graphics | Intel UHD Graphics for 11th Gen (32 execution units, up to 1.45 GHz) |
| Multiplier | Locked |
| ECC memory | Yes |
| Package | FCBGA1787 soldered, 50 × 26.5 mm |
| Cooler in the box | None (laptop cooling) |
Motherboard compatibility
Intel Xeon W-11855M needs a motherboard with a BGA 1787 socket. Chipset by chipset data for this codename is not recorded yet. See the BGA 1787 chipset list and the board maker's CPU support list.
BGA 1787 at a glance
| Type | BGA, 1,787 contacts |
|---|---|
| Package size | 50 × 26.5 mm |
| Introduced | May 2021 |
| Memory | DDR4 up to 3200 MT/s, two channels, up to 128 GB |
| Cooler mounting holes | Not applicable (soldered) |
What the Xeon W-11855M is
The Xeon W-11855M is a 6-core mobile workstation processor that Intel released in May 2021 for thin workstation laptops in the H45 range. Its Willow Cove cores run 3.2 GHz base to 4.9 GHz turbo with Hyper-Threading for 12 threads. Cache is 18 MB of Intel Smart Cache.
The chip is the fastest 6-core of the Tiger Lake workstation mobile stack at launch. The high base clock suits single thread CAD work that depends on one fast core. The 10 nm SuperFin process keeps efficiency in line for mobile bodies with ECC enabled.
Intel UHD Graphics for 11th Gen processors handle display output, with 32 execution units at 350 MHz base and up to 1.45 GHz boost. ECC memory support guards models and data in workstation use. The package is FCBGA1787 soldered at 50 × 26.5 mm.
Socket and motherboard compatibility
The W-11855M fits BGA 1787 only. The chip solders to the laptop board, so there is no socket retention and no later processor upgrade. Board support is fixed to WM590 and related mobile chipsets for this generation, with ECC and vPro enabled through firmware and the board design.
Because the package is soldered, buyers compare complete mobile workstations rather than separate parts. A Dell Precision announcement lists the W-11855M beside Core H45 parts for its 15 and 17 inch workstation laptops. The board, cooler and firmware ship as one unit.
The LGA, PGA and BGA: CPU package types explained guide explains why soldered BGA packages list no cooler mounting pattern. For service, a failed processor means a board replacement through the laptop maker.
Memory, PCIe and cooling
The memory controller supports DDR4 up to 3200 MT/s in two channels, up to 128 GB, with ECC support. Mobile workstations often ship with ECC SODIMM pairs for model integrity across long renders. The controller does not accept DDR5.
The CPU supplies 20 PCIe Gen4 lanes for graphics and storage through the board. Makers usually wire x16 to a professional GPU and x4 to a fast SSD, with Thunderbolt 4 on many designs for docks and fast external drives. The board layout decides the exact split.
Cooling is part of the workstation chassis, not a boxed cooler. The 35 W base with turbo headroom needs dual fans and heat pipes shared with the GPU. Thin workstation bodies hold clocks lower for noise, while larger bodies sustain more. No LGA cooler fits, and the CPU cooler compatibility by socket guide covers why desktop brackets do not apply.
Upgrade paths
Against the Intel Core i7-11600H, the W-11855M adds workstation features with similar 6-core layout. The gaming laptop part carries 18 MB of cache without ECC focus, while this workstation part pairs the same cache with ECC and vPro management. Both share DDR4 limits and Gen4 links.
There is no CPU upgrade path on the soldered board. The next step is a full laptop replacement, either with another H45 workstation of higher core count or a move to a later platform. Storage moves with the drive, while memory moves only when the chassis uses slots.
For workstation buyers, the 6-core Xeon makes sense when single thread speed matters more than core count. When renders need threads, the 8-core W-11955M gives more cores in the same socket family.
Frequently asked questions
What socket does the Intel Xeon W-11855M use?
It uses BGA 1787, a soldered grid array. The chip cannot be replaced.
How many cores does the Intel Xeon W-11855M have?
6 cores with 12 threads at 3.2 GHz base and up to 4.9 GHz turbo, with 18 MB of Intel Smart Cache.
What memory does the Intel Xeon W-11855M support?
DDR4 up to 3200 MT/s with ECC in two channels, up to 128 GB. ECC guards models in workstation use.
What graphics does the Intel Xeon W-11855M include?
Intel UHD Graphics for 11th Gen with 32 execution units up to 1.45 GHz. Workstation laptops pair it with a professional GPU.
What is the TDP of the Intel Xeon W-11855M?
35 W base with turbo headroom. The workstation chassis cooler handles bursts above the base.
Sources and verification
Facts last checked against these sources on . Page last edited on .