Intel Core i5-9400 socket: LGA 1151
The Intel Core i5-9400 uses the LGA 1151 socket on revision 2 boards. It is a locked 65 W 6-core chip without Hyper-Threading for office and family PCs on 300 series boards.
- Socket
- LGA 1151
- Launched
- January 2019
- Cores and threads
- 6 and 6
- Base power
- 65 W
- Codename
- Coffee Lake Refresh
- Segment
- Desktop
- Family
- Intel Core i5
- Clocks
- 2.9 / 4.1 GHz
Intel Core i5-9400 specifications
| Cores | 6 |
|---|---|
| Threads | 6 (no Hyper-Threading) |
| Core architecture | Skylake based cores on 14 nm |
| Clocks | 2.9 GHz base, up to 4.1 GHz (Turbo Boost 2.0) |
| Cache | 9 MB Intel Smart Cache (L3) |
| Processor base power (TDP) | 65 W |
| Manufacturing process | 14 nm |
| Memory support | DDR4 up to 2666 MT/s, two channels, up to 128 GB |
| PCI Express | 16 lanes from the CPU, PCIe 3.0 |
| Integrated graphics | Intel UHD Graphics 630 (up to 1.05 GHz) |
| Multiplier | Locked |
| Package | FCLGA1151 |
| ECC memory | Not supported |
Motherboard and chipset compatibility
Intel Core i5-9400 needs a motherboard with a LGA 1151 socket. The table shows which chipset series accept it.
| Series | Chipsets | Support |
|---|---|---|
| 300 series: B365 and Z390 | Z390, B365 | Works out of the box |
| 300 series: H310, B360, H370, Q370, Z370 | Z370, H370, B360, H310, Q370 | Needs a BIOS update Needs a BIOS update before a 9th Gen processor will start. Check the board maker's CPU support list. |
| 200 series | Z270, H270, B250, Q270, Q250 | Not supported |
| 100 series | Z170, H170, B150, H110, Q170, Q150 | Not supported |
Board makers publish a CPU support list for every model. Check it for your exact board before buying. Chipset details for LGA 1151.
Recommended GPU pairing
| Recommended tier | Mid-range 1080p |
|---|---|
| Example GPUs | GeForce GTX 1660, Radeon RX 580 |
| Target resolution | 1080p high settings |
Six physical cores with boost to 4.1 GHz, 16 PCIe 3.0 lanes and DDR4 line up with mid-range 1080p cards from 2019. A faster card still works and the balance shifts with game, settings and resolution.
This is a rough match for a new build at the stated resolution, not a limit. A faster card still works and helps at higher resolutions or in games that load the GPU more than the CPU. A slower card is fine for lighter games and office use. The exact balance shifts with the game, the settings and the resolution, so no percentage is given.
LGA 1151 at a glance
| Type | LGA, 1,151 contacts |
|---|---|
| Package size | 37.5 × 37.5 mm |
| Introduced | August 2015 |
| Memory | DDR4 on most boards (some early boards use DDR3L). DDR4 only on the second revision |
| Cooler mounting holes | 75 × 75 mm |
What the Core i5-9400 is
The Core i5-9400 is a six core, six thread processor that Intel released in early 2019 with the locked 65 W 9th Gen range. Its cores run 2.9 GHz base to 4.1 GHz turbo with Turbo Boost 2.0. Cache is 9 MB of shared L3.
Like the rest of the 9th Gen i5 line, the 9400 has no Hyper-Threading: six cores yield six threads. The TDP is 65 W on the 14 nm process.
Intel UHD Graphics 630 handle display output, at up to 1.05 GHz. The multiplier is locked. On memory tuning, Z390 and Z370 boards accept XMP kits past DDR4-2666 while H-series and B-series boards hold narrower ranges.
Socket and motherboard compatibility
The 9400 fits the LGA 1151 socket on revision 2 boards only. Z390 and B365 boards accept it with the shipping BIOS. Z370, H370, B360, H310 and Q370 boards need a BIOS update carrying 9th Gen support. Revision 1 boards never support it.
B360 and H370 boards are the expected pairing for a locked chip. Z-series boards add little except ports and memory profiles, since the multiplier stays locked.
Check the maker's CPU support list for the minimum BIOS on early Z370 stock.
Memory, PCIe and cooling
The memory controller supports DDR4 up to 2666 MT/s officially. Two channels carry up to 128 GB. DDR4 boards reuse older kits, while faster XMP kits run on boards that accept them.
The CPU supplies 16 PCIe 3.0 lanes from the processor. Integrated graphics drive office displays without a card, and fast storage hangs off chipset lanes.
At 65 W base with boosts past it, basic cooling suffices with airflow while a tower cooler runs quieter. Mounting uses the 75 mm LGA 1151 pattern from the CPU cooler compatibility by socket guide.
Six cores for offices, revision 2 only
The 9400 brought six physical cores to the mainstream price point without threading, which made it a common office and family PC chip that rarely needed more than stock speeds on cheap boards. Everyday work plus light gaming on integrated graphics needed nothing more.
The LGA 1151 revision split still applies: revision 2 boards only, never 100 or 200 series. Memory overclocking headroom depends on the board, with Z-series boards accepting faster XMP kits while H310 holds official speeds. Memory overclocking headroom depends on the board, with Z-series boards accepting faster XMP kits.
Upgrade paths
Against the Intel Core i5-9400F, the 9400 adds UHD 630 graphics for display output and troubleshooting at a small premium. Against the Intel Core i7-9700K, it gives up two cores and boost headroom for savings on the same socket.
Moving to LGA 1200 needs a new board while keeping DDR4. The 9400 fits an office PC, a family PC, or a budget gaming tower with a mid-range card.
Frequently asked questions
What socket does the Intel Core i5-9400 use?
It uses LGA 1151 on revision 2 boards with 300 series chipsets, written FCLGA1151 in Intel's documents.
What is the difference between the 9400 and the 9400F?
The F has no integrated graphics and needs a separate card. The plain 9400 adds UHD 630 output for a small premium.
Does the 9400 run in a Z270 motherboard?
No. Z270 and other 100 and 200 series boards are revision 1 and never support 9th Gen processors.
What memory speed does the 9400 support?
Officially up to DDR4-2666. Faster kits run through XMP profiles, which count as overclocking.
What cooling and graphics does the 9400 need?
At 65 W base the stock cooling approach works with airflow, while integrated graphics cover office displays without a card.
Sources and verification
Facts last checked against these sources on . Page last edited on .