Intel Core i5-8400 socket: LGA 1151
The Intel Core i5-8400 uses the LGA 1151 socket on revision 2 boards. It is a locked 65 W 6-core Coffee Lake chip without Hyper-Threading that brought six cores to budget builds, on 300 series boards.
- Socket
- LGA 1151
- Launched
- October 2017
- Cores and threads
- 6 and 6
- Base power
- 65 W
- Codename
- Coffee Lake
- Segment
- Desktop
- Family
- Intel Core i5
- Clocks
- 2.8 / 4.0 GHz
Intel Core i5-8400 specifications
| Cores | 6 |
|---|---|
| Threads | 6 (no Hyper-Threading) |
| Core architecture | Skylake based cores on 14 nm |
| Clocks | 2.8 GHz base, up to 4.0 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 64 GB |
| PCI Express | 16 lanes from the CPU, PCIe 3.0 |
| Integrated graphics | Intel UHD Graphics 630 (23 execution units, up to 1.05 GHz) |
| Multiplier | Locked |
| Package | FCLGA1151 |
| ECC memory | Not supported |
Motherboard and chipset compatibility
Intel Core i5-8400 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 | Works out of the box |
| 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 | Entry 1080p |
|---|---|
| Example GPUs | GeForce GTX 1050 Ti, Radeon RX 560 |
| Target resolution | 1080p medium to high settings |
Six physical cores with boost to 4.0 GHz, 16 PCIe 3.0 lanes and DDR4 suit entry 1080p cards from late 2017. 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 i5-8400 is
The Core i5-8400 is a six core, six thread processor that Intel released in October 2017 with the locked 65 W Coffee Lake range. Its cores run 2.8 GHz base to 4.0 GHz turbo with Turbo Boost 2.0. Cache is 9 MB of shared L3.
The 8400 put six physical cores into budget builds for the first time, which stretched its useful life well past quad-core chips of the same price. The TDP is 65 W on the 14 nm process.
Intel UHD Graphics 630 handle display output, with 23 execution units at up to 1.05 GHz. The multiplier is locked. On memory tuning, Z370 boards accept XMP kits past DDR4-2666 while H-series and B-series boards hold narrower ranges.
Socket and motherboard compatibility
The 8400 fits the LGA 1151 socket on revision 2 boards only, and it launched the revision: Z370 boards took it from day one, with Z390, B365, H370, B360, H310 and Q370 following. Revision 1 boards never support it.
B360 and H310 boards are the expected pairing for a budget chip. At launch only Z370 boards existed, which made early 8400 builds pay more for the board than the chip deserved.
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 64 GB. DDR4 boards reuse older kits, which keeps budget builds cheap.
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 modest boosts, basic cooling suffices with airflow for quiet office duty every single day. Mounting uses the 75 mm LGA 1151 pattern from the CPU cooler compatibility by socket guide.
Six cores reach the budget tier
The 8400 shows how core counts moved the budget tier: six threads without threading still beat four-thread chips in new titles, and the low base clock rarely mattered in games that boosted freely.
The H370 and B360 launch in 2018 finally gave it affordable boards to live on. Until then, Z370 was the only option. Within the budget tier the boards differ: B360 carries more USB and SATA ports plus Optane support, while H310 pares back ports and omits Optane, so check board specifications when storage expansion matters.
Upgrade paths
Against the Intel Core i5-8600K, the 8400 trades clocks and overclocking for a 65 W rating and a much lower price on the same socket. Against the Intel Core i7-8700K, it gives up threading for savings.
Moving to LGA 1200 needs a new board while keeping DDR4. The 8400 fits an office PC, a family PC, or a first gaming build on a tight budget.
Frequently asked questions
What socket does the Intel Core i5-8400 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 8400 and the 8600K?
The 8400 runs lower clocks at 65 W with a locked multiplier. The 8600K adds clocks and overclocking at 95 W.
Does the 8400 run in a Z270 motherboard?
No. Z270 and other 100 and 200 series boards are revision 1 and never support Coffee Lake processors.
What memory speed does the 8400 support?
Officially up to DDR4-2666. Faster kits run through XMP profiles, which count as overclocking.
What cooling and graphics does the 8400 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 .