Intel Core Ultra 9 285T socket: LGA 1851
The Intel Core Ultra 9 285T uses LGA 1851 (FCLGA1851). It is a 24-core Arrow Lake desktop processor with a 35 W base power for compact workstations that need flagship threads at lower draw.
- Socket
- LGA 1851
- Launched
- January 2025
- Cores and threads
- 24 and 24
- Base power
- 35 W
- Codename
- Arrow Lake
- Segment
- Desktop
- Family
- Intel Core Ultra 9
- Clocks
- 1.4 / 5.4 GHz
Intel Core Ultra 9 285T specifications
| Cores | 24 (8 Performance-cores plus 16 Efficient-cores) |
|---|---|
| Threads | 24 |
| P-core clocks | 1.4 GHz base, up to 5.3 GHz turbo (up to 5.4 GHz Turbo Boost Max 3.0) |
| E-core clocks | 1.2 GHz base, up to 4.6 GHz turbo |
| Cache | 36 MB Intel Smart Cache (L3) and 40 MB total L2 |
| Processor base power (TDP) | 35 W |
| Maximum turbo power | 112 W |
| Manufacturing process | 3 nm (TSMC N3B) |
| Memory support | DDR5 up to 6400 MT/s, two channels |
| PCI Express | 24 lanes from the CPU: PCIe 5.0 and PCIe 4.0 |
| Platform AI throughput | 35 TOPS (Int8) |
| Package | FCLGA1851 |
| Multiplier | Locked |
Motherboard and chipset compatibility
Intel Core Ultra 9 285T needs a motherboard with a LGA 1851 socket. The table shows which chipset series accept it.
| Series | Chipsets | Support |
|---|---|---|
| 800 series | Z890, B860, H810, Q870, W880 | 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 1851.
LGA 1851 at a glance
| Type | LGA, 1,851 contacts |
|---|---|
| Package size | 45.0 × 37.5 mm |
| Introduced | October 2024 |
| Memory | DDR5 only |
| Cooler mounting holes | 78 × 78 mm |
What the Core Ultra 9 285T is
The Intel Core Ultra 9 285T is the power-optimized 24-core flagship of the Core Ultra 200S Arrow Lake desktop stack on Socket LGA 1851. It runs 24 cores at 1.4 GHz Performance-core base with boost to 5.3 GHz and Turbo Boost Max 3.0 to 5.4 GHz alongside 1.2 GHz Efficient-core base to 4.6 GHz, backed by 36 MB of Intel Smart Cache plus 40 MB of L2 and a 35 W base power with 112 W maximum turbo power. Intel launched the 35 W range in January 2025 at a 549 USD recommended price, built on TSMC N3B.
Twenty-four cores at 35 W suit compact workstations, quiet creation PCs and small labs where flagship thread count must fit a slim thermal budget. The low 1.4 GHz P-core base keeps the envelope in reach for compact coolers, while favored-core boosts to 5.4 GHz clear interactive spikes. Platform AI throughput of 35 TOPS covers on-device assistance.
Against the 65 W Intel Core Ultra 9 285 twin above it, the 285T trades base clocks for a 30 W lower envelope at identical core counts. Against the 35 W 20-core Intel Core Ultra 7 265T below it, the 285T adds 4 E-cores for denser parallel work. T-series parts ship in trays for system integrators. See Socket vs chipset: what decides whether a CPU works for why chipset series plus BIOS revision together decide board fit.
Socket and motherboard compatibility
The 285T fits LGA 1851 in the FCLGA1851 package, the same socket as the rest of the Core Ultra 200S family. Boards with 800 series chipsets such as B860, Q870 and H810 take Arrow Lake at matching power classes, but the 285T must appear by name on the vendor CPU list rather than being assumed from socket fit.
Memory is DDR5 up to 6400 MT/s in two channels. LGA 1851 is DDR5 only, so DDR4 kits from older towers do not carry over. A move from any other socket is a full platform change with board, memory and cooler replaced together.
Memory, PCIe and cooling
Memory on LGA 1851 for this class is DDR5 up to 6400 MT/s in two channels. Two channels keep 24 threads supplied in creation and lab mixes where the working set fits small tower memory sizes. Population order follows the board manual.
PCI Express connectivity is 24 lanes from the CPU across PCIe 5.0 and 4.0. That lane budget feeds a compact discrete card or an NVMe boot drive without strain. Lane splits follow the board block diagram, so builders confirm slot wiring before adding cards.
Cooling uses standard LGA 1851 retention, and the 35 W class suits low-profile air coolers in slim chassis. Firmware power limits scale between 35 W base and the 112 W turbo ceiling. An AI Boost NPU covers entry on-device assistance beside CPU and graphics.
Upgrade paths
On the same socket, the path up from the 285T is the 65 W Intel Core Ultra 9 285 twin for higher sustained clocks on LGA 1851 boards where cooling allows. There is no larger Arrow Lake desktop above 24 cores in this batch, so further growth means a second machine.
The step down to the 35 W Intel Core Ultra 7 265T trims 4 E-cores for a lower price. A move to LGA 1700 is a different platform with DDR4 options. That change replaces board, memory and cooling from scratch.
Frequently asked questions
What socket does the Intel Core Ultra 9 285T use?
FCLGA1851 (LGA 1851), the land grid array socket for Core Ultra 200S Arrow Lake desktops with 800 series chipsets such as Z890, B860, W880, Q870 and H810.
How are the 24 cores of the 285T arranged?
Eight Lion Cove Performance-cores plus 16 Skymont Efficient-cores with no low-power island cores, giving 24 cores and 24 threads. There is no Hyper-Threading, so each core runs one thread.
What memory does the 285T need?
DDR5 up to 6400 MT/s in two channels. Exact speeds and capacity follow the board design.
Can the 285T be overclocked?
No. The multiplier is locked, which rules out overclocking. Power limits still scale between the 35 W base and the 112 W turbo ceiling.
Sources and verification
- Intel Core Ultra 9 285T (Arrow Lake, 24 cores to 5.4 GHz, 36 MB, 35 W, $549)
- Intel Core Ultra 9 285 (Arrow Lake twin, 24 cores, 36 MB, 65 W, TSMC N3B)
- Supermicro Core Ultra Series 2 table (285T 24 cores, 35 W; 285 24 cores, 65 W; DDR5-6400)
Facts last checked against these sources on . Page last edited on .