Intel Core i9-9940X socket: LGA 2066

What the Core i9-9940X is

The Core i9-9940X is a fourteen core, twenty eight thread HEDT processor with a 3.3 GHz base, up to 4.4 GHz turbo and up to 4.5 GHz on favored cores. It carries 19.25 MB of shared L3 cache and a 165 W TDP on the 14 nm process. Intel announced it on October 8, 2018 with the 9th Gen Core X refresh.

Fourteen cores suit long renders and compiles that scale across threads, with turbo covering lighter bursts. The chip shares its cache size with the twelve core bin, trading cache per core for thread count. The multiplier is unlocked for tuning on X299 boards.

There is no integrated graphics, so a separate card is required. The database lists a $1387 launch price. Boards need an X299 BIOS with 9th Gen X support from late 2018.

Socket and motherboard compatibility

The 9940X fits LGA 2066 on X299 motherboards with quad channel DDR4. Boards sold before the 9th Gen launch need a BIOS update with the new IDs before the chip will start. The Socket vs chipset: what decides whether a CPU works guide explains chipset support by generation.

Fourteen cores reward boards with heatsinked voltage stages and fair case airflow for long sessions. Entry X299 boards that merely boot it will throttle under sustained renders, so mid range boards and up are the sensible pairing.

The chip ships without any cooler and mounts on the large LGA 2066 pattern. The Intel Core i9-10940X is the later 14 core successor on the same boards with faster memory support.

Memory, PCIe and cooling

Memory support is DDR4-2666 in four channels up to 128 GB, with up to 85 GB per sec of bandwidth. ECC is not supported. Renders love capacity, so 4 by 16 GB with room to double suits this core count where the board has eight slots.

PCI Express arrives as version 3.0 with 44 lanes from the CPU for graphics and NVMe arrays. Two graphics cards and three fast SSDs fit the lane budget of a workstation tower. Cooling needs a large tower or liquid loop at 165 W.

Upgrade paths

On the same socket the step up is a sixteen core chip such as the Intel Core i9-9960X where thread count matters, keeping the board and DDR4. The 9940X keeps its place where fourteen cores cover workstation loads below the larger dies.

Moving past LGA 2066 means a new board and usually DDR5 on current platforms. Owners usually add memory or storage before replacing the processor.