LGA 2066, also called Socket R4, is a CPU socket by Intel that debuted with Skylake-X and Kaby Lake-X processors in June 2017. It replaces Intel's LGA 2011-3 (R3) in the performance, high-end desktop and Workstation platforms (based on the X299 "Basin Falls" and C422 chipsets), while LGA 3647 (Socket P) replaces LGA 2011-3 (R3) in the server platforms based on Skylake-SP (Xeon "Purley").

LGA 2066 and LGA 1151 are the last two Intel sockets to officially support Windows 7, Windows Server 2008 R2, Windows 8, Windows Server 2012, Windows 8.1 and Windows Server 2012 R2 and the earliest two Intel sockets to officially support all versions of Windows 11.

Compatible processors

High-End Desktop (HEDT) All of these CPUs require the Intel X299 chipset to work. So, the C422 chipset is strictly limited to work with workstation processors only.

Kaby Lake-X Kaby Lake-X processors were discontinued in May 2018. Starting October 2019, BIOS updates for most of the X299-based motherboards removed support for Kaby Lake-X processors."X299 BIOS Update for Intel Cascade Lake-X Will Kill Kaby Lake-X Support".Tom's Hardware. NameCores (threads)Base ClockTurbo Boost 2.0TurboBoost 3.0MemorysupportL2 cacheL3cache(MB)PCIe 3.0lanesTDPReleasedatePrice(USD)Single coreAll coresCore i5-7640X4 (4) 4.0 GHz 4.2 GHz4.0 GHz rowspan="2" 2 × DDR4-2666 up to 64 GB256 KB per core6 16 112 W Q2'17 $242Core i7-7740X4 (8) 4.3 GHz 4.5 GHz 8 $339

Skylake-X 7000-series NameCores (threads)Base ClockTurbo Boost 2.0TurboBoost 3.0MemorysupportL2 cacheL3cache(MB)PCIe 3.0lanesTDPReleasedatePrice(USD)Single coreAll coresCore i7-7800X6 (12) 3.5 GHz 4.0 GHzN/A 4 × DDR4-2400 up to 128 GB 1 MB per core8.25 28 140 WQ2'17$389Core i7-7820X8 (16) 3.6 GHz 4.3 GHz4.0 GHz 4.5 GHz 4 × DDR4-2666 up to 128 GB 11 $599Core i9-7900X 10 (20) 3.3 GHz 13.75 44 $999Core i9-7920X 12 (24) 2.9 GHz 3.8 GHz 4.4 GHz 16.5 Q3'17 $1199Core i9-7940X 14 (28) 3.1 GHz 19.25 165 W $1399Core i9-7960X 16 (32) 2.8 GHz 4.2 GHz 3.6 GHz 22 $1699Core i9-7980XE 18 (36) 2.6 GHz 3.4 GHz 24.75 $1999

Skylake-X 9000-series NameCores (threads)Base ClockTurbo Boost 2.0TurboBoost 3.0MemorysupportL2 cacheL3cache(MB)PCIe 3.0lanesTDPReleasedatePrice(USD)Single coreAll coresCore i7-9800X8 (16)3.8 GHz4.4 GHz4.5 GHz4 × DDR4-2666 up to 128 GB1 MB per core16.544165 WQ4'18$589Core i9-9820X10 (20)3.3 GHz4.1 GHz4.2 GHz$889Core i9-9900X3.5 GHz4.4 GHz4.5 GHz19.25$989Core i9-9920X12 (24)$1189Core i9-9940X14 (28)3.3 GHz$1387Core i9-9960X16 (32)3.1 GHz22$1684Core i9-9980XE18 (36)3.0 GHz3.8 GHz24.75$1999

Cascade Lake-X NameCores (threads)Base ClockTurbo Boost 2.0TurboBoost 3.0MemorysupportL2 cacheL3cache(MB)PCIe 3.0lanesTDPReleasedatePrice(USD)Single coreAll coresCore i9-10900X10 (20)3.7 GHz4.5 GHz4.3 GHz4.7 GHz4 × DDR4-2933 up to 256 GB1 MB per core19.2548165WQ4'19$599Core i9-10920X12 (24)3.5 GHz4.6 GHz4.8 GHz$700Core i9-10940X14 (28)3.3 GHz4.1 GHz$797Core i9-10980XE18 (36)3.0 GHz3.8 GHz24.75$1000

Workstation Take note that certain types of Xeon processors will not work on this socket, like Skylake-P. There are four OEM variants that can be found in Apple Mac Pro: W-2140B and W-2150B (lower freq/TDP than their W-21x5 counterparts), W-2170B and W-2191B lack Trusted_Execution_Technology (TXT) in comparison.

Skylake-W NameCores (threads)Base ClockTurbo Boost 2.0MemorysupportL2 cacheL3cache(MB)PCIe 3.0lanesTDPReleasedatePrice(USD)Single coreAll coresXeon W‑21024 (4)2.9 GHzN/A4 x DDR4‑2400 up to 512 GB1 MB per core8.2548120 WQ3'17$202Xeon W‑21043.2 GHz$255Xeon W‑21234 (8) 3.6 GHz 3.9 GHz 3.7 GHz 4 × DDR4‑2666 up to 512 GB$294Xeon W‑2125 4.0 GHz 4.5 GHz 4.4 GHz$444Xeon W‑21336 (12) 3.6 GHz 3.9 GHz 3.8 GHz 140 W $617Xeon W‑2135 3.7 GHz 4.5 GHz 4.4 GHz$835Xeon W‑2140B*8 (16) 3.2 GHz 4.2 GHz 3.8 GHz11 120 WN/AXeon W‑21453.7 GHz 4.5 GHz4.3 GHz 140 W $1113Xeon W‑2155 10 (20) 3.3 GHz 4.0 GHz13.75 Q4'17$1440Xeon W‑2175 14 (28) 2.5 GHz4.3 GHz3.3 GHz 19.25$1950Xeon W‑2195 18 (36) 2.3 GHz 3.2 GHz 24.75Q3'17$2553

(* = OEM CPU found in Apple Mac Pro with lower TDP)

Cascade Lake-W NameCores (threads)Base ClockTurbo Boost 2.0Turbo Boost 3.0MemorysupportL2 cacheL3cache(MB)PCIe 3.0lanesTDPReleasedatePrice(USD)Single coreAll coresXeon W-22234 (8)3.6 GHz3.9 GHz3.7 GHzN/A4 × DDR4‑2666 up to 1 TB1 MB per core8.2548120 WQ4'19$297Xeon W-22254.1 GHz4.6 GHz4.5 GHz4 x DDR4-2933 up to 1 TB105 W$444Xeon W-22356 (12)3.8 GHz4.3 GHz130 W$555Xeon W-22458 (16)3.9 GHz4.5 GHz4.5 GHz4.7 GHz16.5155 W$667Xeon W-225510 (20)3.7 GHz4.3 GHz19.25165 W$778Xeon W-226512 (24)3.5 GHz4.6 GHz4.8 GHz$944Xeon W-227514 (28)3.3 GHz4.1 GHz$1112Xeon W-229518 (36)3.0 GHz3.8 GHz24.75$1333

References