Intel Core i9-9900KS socket: LGA 1151
The Intel Core i9-9900KS uses the LGA 1151 socket on revision 2 boards. It is a binned special edition of the 8-core Coffee Lake Refresh flagship that holds 5.0 GHz on all cores, on 300 series boards.
- Socket
- LGA 1151
- Launched
- October 30, 2019
- Cores and threads
- 8 and 16
- Base power
- 127 W
- Codename
- Coffee Lake Refresh
- Segment
- Desktop
- Family
- Intel Core i9
- Clocks
- 4.0 / 5.0 GHz
Intel Core i9-9900KS specifications
| Cores | 8 |
|---|---|
| Threads | 16 |
| Core architecture | Skylake based cores on 14 nm |
| Clocks | 4.0 GHz base, up to 5.0 GHz all-core turbo |
| Cache | 16 MB Intel Smart Cache (L3) |
| Processor base power (TDP) | 127 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 1.20 GHz) |
| Multiplier | Unlocked (KS special edition) |
| Package | FCLGA1151 |
| Cooler in the box | None (the boxed product includes no fan or heatsink) |
| Launch price | $513 (Intel RCP) |
Motherboard and chipset compatibility
Intel Core i9-9900KS 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 | High-end 1440p |
|---|---|
| Example GPUs | GeForce RTX 2080 Ti, Radeon RX 5700 XT |
| Target resolution | 1440p high settings |
Eight binned cores with 5.0 GHz all-core turbo, 16 PCIe 3.0 lanes and DDR4 match high-end 1440p cards from late 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 i9-9900KS is
The Core i9-9900KS is an eight core, sixteen thread special edition that Intel released in October 2019. It uses selected Coffee Lake silicon with a 4.0 GHz base and up to 5.0 GHz all-core turbo, against 3.6 GHz base on the regular K. Cache is 16 MB of shared L3.
Only binned dies hold 5.0 GHz across all cores inside stock power behavior, which is why Intel sold it for a limited time. The TDP is 127 W on the 14 nm process, up from 95 W on the K.
Intel UHD Graphics 630 cover display output, at up to 1.20 GHz. The multiplier is unlocked. The launch price was $513 (Intel RCP). The boxed product includes no fan or heatsink.
Socket and motherboard compatibility
The 9900KS fits the LGA 1151 socket on revision 2 boards only. Z390 boards are the expected match, since Intel listed compatibility with existing Z390 motherboards at launch. Other 300 series boards (B365, Z370, H370, B360, H310, Q370) can run it subject to BIOS support, with Z370 and older 300 series boards needing an update. Revision 1 boards with 100 or 200 series chipsets never support it.
A Z-series board is required to use the unlocked multiplier, and strong voltage stages matter at 127 W base with high all-core current. Check the maker's CPU support list for the minimum BIOS version.
Supply was limited, so used boards with a confirmed BIOS are worth more to a KS buyer than new old stock without one.
Memory, PCIe and cooling
The memory controller supports DDR4 up to 2666 MT/s officially. Two channels carry up to 128 GB. Faster kits run through XMP profiles, which Z-series boards accept.
The CPU supplies 16 PCIe 3.0 lanes from the processor, with up to 40 platform lanes in total. Integrated graphics cover display output at up to 1.20 GHz.
Cooling is the defining requirement: 127 W base with all-core 5.0 GHz needs a large air cooler or liquid cooler. Intel ships no cooler with the box. Mounting uses the 75 mm LGA 1151 pattern from the CPU cooler compatibility by socket guide.
Binned silicon at the socket ceiling
The KS exists because binning exists. Only select chips from Intel's wafers held 5.0 GHz on every core, so the special edition put a factory guarantee behind what overclockers chased manually on the K. Availability lasted only while binned stock did.
The LGA 1151 revision split still applies: revision 2 boards only, never 100 or 200 series. Within revision 2 the KS is the clock ceiling, with no faster stock chip above it on the socket.
Upgrade paths
Next to the Intel Core i9-9900K, the KS buys a higher base clock and guaranteed all-core 5.0 GHz at a premium and higher TDP. Most builders kept the K and spent the difference on cooling or graphics.
Moving to LGA 1200 or LGA 1700 needs a new board, and DDR5 builds need new memory too. The KS fits collectors and overclockers who want the fastest stock 9th Gen chip.
Frequently asked questions
What socket does the Intel Core i9-9900KS 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 9900KS and the 9900K?
The KS is binned silicon with 5.0 GHz all-core turbo and a 4.0 GHz base against 3.6 GHz on the K, at 127 W instead of 95 W.
Does the 9900KS run in a Z270 motherboard?
No. Z270 and other 100 and 200 series boards are revision 1 and never support 9th Gen processors.
Which boards fit the 9900KS best?
Z390 was the expected match at launch. Other 300 series boards work subject to BIOS support, with older ones needing an update.
Does the 9900KS come with a cooler?
No. Intel states the boxed product includes no fan or heatsink, and all-core 5.0 GHz needs a large air cooler or liquid cooler.
Sources and verification
- Intel Core i9-9900KS specifications (Intel)
- Intel announces 9900KS pricing and availability (PC Perspective)
Facts last checked against these sources on . Page last edited on .