Intel Core i5-8420 socket: LGA 1151
The Intel Core i5-8420 uses the LGA 1151 socket, second revision. It runs on 300 series boards as a 65 W six core with UHD Graphics 630 for office and light threaded work.
- Socket
- LGA 1151
- Launched
- September 2018
- Cores and threads
- 6 and 6
- Base power
- 65 W
- Codename
- Coffee Lake
- Segment
- Desktop
- Family
- Intel Core i5
- Clocks
- 2.9 / 4.1 GHz
Intel Core i5-8420 specifications
| Cores | 6 |
|---|---|
| Threads | 6 |
| Core architecture | Coffee Lake |
| Clocks | 2.9 GHz base, up to 4.1 GHz turbo |
| Cache | 9 MB L3 (shared) |
| Processor base power (TDP) | 65 W |
| Manufacturing process | 14 nm |
| Memory support | DDR4 up to 2666 MT/s, two channels |
| PCI Express | PCIe 3.0, 16 lanes from the CPU |
| Integrated graphics | Intel UHD Graphics 630 |
| Multiplier | Locked |
| Package | FCLGA1151 |
Motherboard and chipset compatibility
Intel Core i5-8420 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.
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 i5-8420 is
The Core i5-8420 is a six core, six thread desktop processor with a 2.9 GHz base and up to 4.1 GHz turbo. It carries 9 MB of shared L3 cache and a 65 W TDP on the 14 nm process. The TechPowerUp database lists part number SR3X4 with a September 1, 2018 release.
It sits 100 MHz above the i5-8400 base with a similar turbo, which makes it a small step for office towers bought in late 2018. Six cores cover office multitasking, compilation and light media work without the cost of an i7. The multiplier is locked at 29 times the 100 MHz base clock.
UHD Graphics 630 covers office displays without a separate card. ECC is listed as not supported. Intel also names this SKU in its MDDS document for the 8th Gen i5 family, which confirms it as a real volume part rather than a database error.
Socket and motherboard compatibility
The 8420 fits LGA 1151 revision 2 on 300 series motherboards such as H310, B360 and H370. Boards sold in late 2018 accept it with the shipping BIOS where the maker lists the part. The Socket vs chipset: what decides whether a CPU works guide explains the two revisions of this socket.
It does not fit 100 or 200 series boards, which are revision 1 for 6th and 7th Gen chips. Office fleets should check the board CPU list for the exact 8420 before ordering, because some early 300 series releases predate this SKU.
B360 boards with four DIMM slots suit this chip where memory growth matters. A single tower cooler on the shared 75 mm pattern covers the 65 W load. The Intel Core i5-8400 is a nearby alternative with wider board listings at slightly lower clocks.
Memory, PCIe and cooling
Memory support is DDR4 in two channels at up to 2666 MT/s, with about 42.7 GB per sec of bandwidth. ECC is listed as not supported, so standard desktop DIMMs are the fit. Two matched sticks give dual channel speed for six core multitasking.
PCI Express arrives as version 3.0 with 16 lanes from the CPU for graphics and storage. A single NVMe drive and a mid range card fit the lane budget of a mainstream tower. Cooling uses the shared 75 mm LGA 1151 pattern at 65 W, so stock coolers and common towers fit.
Upgrade paths
On the same socket the step up is a six core twelve thread chip such as the Intel Core i7-8700 where threaded throughput matters, keeping the board and DDR4. The 8420 keeps its place where six threads cover the work at lower cost. Gamers on this chip usually upgrade the graphics card before the processor.
Moving past LGA 1151 to LGA 1200 needs a new board, since no 8th Gen chip fits the newer socket. Office owners usually add memory or an SSD before replacing the processor.
Frequently asked questions
What socket does the Core i5-8420 use?
It uses LGA 1151 revision 2 on 300 series boards. It does not work on 100 or 200 series boards.
How many cores does the 8420 have?
Six cores and six threads at 2.9 GHz base with up to 4.1 GHz turbo, with 9 MB of cache at 65 W.
Which graphics does the 8420 include?
UHD Graphics 630 for office displays without a separate card. A discrete card still fits the 16 PCIe 3.0 lanes where play or creation needs it.
What memory does the 8420 support?
DDR4 up to 2666 MT/s in two channels. ECC is listed as not supported.
How does the 8420 differ from the Core i5-8400?
The Intel Core i5-8400 runs 2.8 GHz base with up to 4.0 GHz turbo on the same boards. The 8420 adds 100 MHz on both ends.
Sources and verification
- Intel Core i5-8420 specs (TechPowerUp CPU database)
- Intel Core Processors i5-8400 to i5-8650K MDDS (Intel)
Facts last checked against these sources on . Page last edited on .