Intel LGA2066: The Complete CPU List

This LGA2066 CPU list covers every processor made for the socket: the Core i5, i7 and i9 X-series of the 7th, 9th and 10th gen for X299 boards, and the Xeon W-2100 and W-2200 for C422 boards, including the four chips Intel made for Apple’s iMac Pro. Use the filters to narrow it down by family, architecture, core count, TDP, PCIe lanes or features, or type a model number or the sSpec code printed on the CPU into the search box.

One socket, two platforms: X299 and C422

Intel launched LGA2066 (Socket R4) in June 2017 as the single-socket successor to LGA2011-3. On paper its two chipsets are almost twins, with 24 PCIe 3.0 lanes each and the same DMI 3.0 link to the CPU, but they don’t share processors. Intel pairs the Core X-series only with X299 and the Xeon W only with C422, so a Core i9 won’t run on a C422 board and a Xeon W won’t run on an X299 board.

• X299 and Core X: every chip has an unlocked multiplier. Memory is ordinary unbuffered DDR4 without ECC.
• C422 and Xeon W: locked multipliers, ECC support and up to 512 GB of memory on the W-2100 or 1 TB on the W-2200. Most C422 boards and workstations take only registered memory (RDIMM or LRDIMM), so plan on that rather than desktop sticks and check the board’s memory list.

No LGA2066 processor has integrated graphics, so every build needs a graphics card.

Many used Xeon W chips, such as the W-2135 and W-2145, come out of retired workstations like the HP Z4 G4, Dell Precision 5820 and Lenovo ThinkStation P520, which is why they are so cheap and easy to find.

Generations compared

• Kaby Lake-X (i5-7640X, i7-7740X) is the odd one out: in effect an i5-7600K or i7-7700K with the graphics switched off, moved to the big socket. It has dual-channel memory, 16 lanes and no AVX-512.
• Skylake-X brought up to 18 cores, a mesh in place of the ring bus, 1 MB of L2 cache per core and a smaller, non-inclusive L3. Under the lid is thermal paste, and the big chips run hot. The i7-7800X and i7-7820X have only 28 lanes.
• Skylake-X Refresh has the same cores, but every model uses the large die and is soldered. The large die gives the 8-core i7-9800X more cache than the i7-7820X, and Intel gave every 9th gen model the full 44 lanes.
• Cascade Lake-X raised clocks and memory support and added DL Boost (VNNI) instructions. Intel also cut prices hard: the i9-10980XE was announced at $979, against $1,979 for the i9-9980XE.
• i9-9990XE: a 14-core chip running 5 GHz on all cores at 255 W. Intel sold it only through closed auctions to system builders, never at retail, so it is rare, and Intel has no spec page for it.
• Xeon W-2140B, W-2150B, W-2170B and W-2191B come from the iMac Pro. They are ordinary socketed chips. The 8- and 10-core versions run lower base clocks and a lower TDP than their retail twins. Owners report them working on C422 boards such as the Supermicro X11SRA, ASUS WS C422 PRO/SE and ASRock Rack C422 WSI/IPMI, but no board maker officially supports them, so update the BIOS first.

Will it run on my board?

• BIOS. 9th and 10th gen chips need a BIOS update on X299 boards from 2017, and the big board makers released one for most of their models. An i9-10900X or 10980XE won’t boot on the old firmware, so update with the old CPU still in place, or use the board’s BIOS Flashback feature if it has one. On C422 the same goes for the W-2200: boards from 2017 need a newer BIOS for it, and a few, like the ASRock Rack C422 WSI/IPMI, list only the W-2100, so check the CPU support list first.
• Kaby Lake-X needs an early board. The original 2017 X299 boards keep the i5-7640X and i7-7740X on their support lists even after the 10th gen BIOS. The later boards, such as the ASUS Prime X299 Edition 30 and Prime X299-A II, MSI X299 Pro 10G and the Gigabyte X299X series, don’t take them at all, though they still run the 7th gen Skylake-X from the i7-7800X up. The opposite trap also exists: the MSI X299M-A PRO and the Gigabyte X299 AORUS Gaming (not to be confused with the AORUS Gaming 3, 7 and 9) take Kaby Lake-X only and won’t run a six-core or bigger chip with any BIOS, so check the exact model name before buying a used board.
• Kaby Lake-X on X299. With dual-channel memory only half the memory slots work, and the 16 lanes leave some PCIe and M.2 slots dead. Treat these chips as a placeholder until a proper X-series CPU goes in.
• PCIe lanes. With a 28-lane i7-7800X or i7-7820X, boards switch off a slot or run some at x8 or x4. The board manual has a lane table for each CPU type. Cascade Lake-X has 48 lanes, but boards designed before it were wired for 44, so the extra four usually go unused.
• Memory. Officially the limit is 64 GB with Kaby Lake-X, 128 GB with Skylake-X and its 9th gen refresh, and 256 GB with 10th gen. Core X doesn’t support ECC on any board.
• Power and VRM. The first X299 boards had weak VRM cooling, and with an overclocked chip some of them got so hot the CPU throttled. At stock settings a 140 or 165 W chip is fine on any decent board, but many boards raise Intel’s power limits by default, so check the BIOS. An overclocked 18-core chip can draw 500 W or more. For that, use a board with two CPU power connectors (8+8 or 8+4 pin) and a fan blowing over the VRM.
• Workstations. In an HP, Dell or Lenovo workstation, the maker’s own CPU support list decides what runs. There, the BIOS, power delivery and cooling matter more than the socket.

Which CPU to choose

• The fastest on X299: the i9-10980XE. It has 18 cores, 48 lanes, solder under the lid and support for 256 GB. It needs the 10th gen BIOS.
• Fewer cores, higher clocks: the i9-10900X and i9-10920X. Don’t buy any LGA2066 chip for gaming alone, though. Mainstream desktop chips from the same years are as fast as or faster than these in games. This platform pays off with cores, memory channels and PCIe lanes.
• A cheap X299 upgrade: an i7-9800X rather than an i7-7820X. Both have 8 cores, but the 9800X has 44 lanes instead of 28 and solder instead of paste.
• Xeon on C422: the W-2135 (6 cores, 4.5 GHz turbo) and W-2145 (8 cores) are the cheap, common choices. The top of the line is the W-2295: 18 cores, 4.8 GHz with Turbo Boost Max 3.0 and up to 1 TB of memory.
• Skip the i5-7640X and i7-7740X unless you need one to flash a BIOS, and the W-2102 and W-2104, which have four cores, no Hyper-Threading and no turbo.

Coming from X99? Our LGA2011-3 guide covers the Xeon E5 v3/v4 and Core i7 chips that LGA2066 replaced. Need more cores? The bigger platform of the same years is LGA3647: our LGA3647 CPU list covers Xeon Scalable, the W-3175X and the W-3200.

FAQ

Do LGA2011-3 coolers fit LGA2066?

Yes. LGA2066 uses the same square mount as LGA2011 and LGA2011-3, with 80 × 80 mm hole spacing, so any cooler for those sockets fits. A few C422 server boards, such as the Supermicro X11SRM-F, use the narrow ILM instead, which needs a different mounting kit.

Does LGA2066 run Windows 11?

Yes. In August 2021 Microsoft added the Core X-series and Xeon W to its Windows 11 requirements, and the supported processor list for versions 22H2 and 23H2 includes the Core 7000X, 9000X and 10000X series and the Xeon W-2100 and W-2200. The 24H2 list left them out. Microsoft has said these lists are guidance for manufacturers building new PCs and don’t affect existing installations, and its current list of supported Intel processors names them again. For the TPM, both X299 and C422 have Intel PTT, which you switch on in the BIOS.

Can I use ECC memory with a Core i9?

No. Neither the Core X-series nor X299 supports ECC. For ECC you need a Xeon W on a C422 board.

Does Linux run on every LGA2066 CPU?

Yes. Every chip here supports the full x86-64-v3 instruction set, so even distributions built for it, such as RHEL 10, run on all of them.

Which LGA2066 CPUs support AVX-512?

All of them except the i5-7640X and i7-7740X. Software that uses these instructions, such as some video encoders and the PS3 emulator RPCS3, runs faster on them. The Xeon W-2102 and W-2104 have AVX-512, but with one AVX-512 FMA unit per core instead of two, so heavy AVX-512 code runs slower on them.