LGA 2011
LGA 2011 is a land grid array (LGA) CPU socket developed by Intel, featuring 2011 pins and also known as Socket R. Introduced on November 14, 2011, alongside the Sandy Bridge-E processor series, it succeeded the LGA 1366 socket to provide a platform for high-end desktop (HEDT) and server processors supporting multi-core configurations and quad-channel memory.[1][2][3] The socket encompasses several variants to accommodate evolving processor architectures and memory standards, including LGA 2011-0 for initial Sandy Bridge-E and Ivy Bridge-E Core i7 processors using DDR3 memory with X79 (desktop) and C600-series (server) chipsets; LGA 2011-1 for Xeon E7 v2 family with DDR3 and C610 chipsets; and LGA 2011-3 (or LGA 2011-v3) for Haswell-E, Broadwell-E Core i7 processors, and Xeon E5 v3/v4 families supporting DDR4 memory with revised C610 chipsets.[4][5][6] These variants maintain the 2011-pin layout but differ in keying notches, integrated load mechanisms (ILM), and pin assignments to ensure incompatibility and prevent cross-usage, with LGA 2011-3 introducing support for up to 1.5 TB of DDR4 RAM in server configurations.[7] Key features of the LGA 2011 platform include support for up to 40 PCIe 3.0 lanes, integrated PCI devices for I/O, and thermal solutions with specified static pre-load compressive loads via the ILM for reliable contact.[6][3] The socket enabled enthusiast and professional workloads through processors like the Core i7-3960X (six cores at up to 3.9 GHz) and Xeon E5-2699 v4 (22 cores at up to 3.6 GHz), with package sizes of 52.5 mm × 45.0 mm and TDPs ranging from 130 W to 145 W.[8][9] Production of LGA 2011 processors ended around 2016, with the platform succeeded by LGA 2066 for subsequent HEDT generations.[5]Overview
Introduction
LGA 2011, also known as Socket R, is a land grid array (LGA) CPU socket featuring 2011 pins, designed by Intel for high-performance computing applications.[3] It serves as the interface between the processor and motherboard, enabling direct electrical connections without soldered pins on the CPU package, which facilitates easier upgrades and replacements.[3] Introduced on November 14, 2011, the socket debuted alongside Intel's Sandy Bridge-E processor architecture and the X79 chipset for desktop platforms.[10] The socket's primary applications include high-end desktop (HEDT) systems for enthusiast gaming and professional workstations, as well as scalable server environments supporting multi-socket configurations up to eight CPUs in enterprise setups.[11] Key innovations encompass quad-channel DDR3 memory support in its original variant, transitioning to DDR4 in later iterations, alongside high core counts reaching up to 22 cores per CPU in server-oriented models.[10][12] Additionally, it provides up to 40 PCIe 3.0 lanes per socket, enhancing connectivity for graphics, storage, and networking demands in performance-critical workloads.[10] Spanning from its 2011 launch through 2016, LGA 2011 was gradually phased out by 2017, succeeded by LGA 2066 for HEDT platforms and LGA 3647 for advanced server processors.[13] Positioned to bridge consumer enthusiast markets with enterprise data centers, it catered to professionals requiring robust multi-threading, gamers seeking extreme overclocking potential, and organizations deploying reliable multi-CPU servers.[11]Historical development
The LGA 2011 socket family originated as Intel's response to the limitations of the preceding LGA 1366 socket, which had been introduced in 2008 for high-end desktop (HEDT) and server platforms but struggled with escalating demands for multi-core processing and memory throughput in the face of AMD's advancements. AMD's Opteron 6100-series processors, launched in 2010, featured quad-channel DDR3 memory support, prompting Intel to shift from the triple-channel architecture of LGA 1366 to quad-channel DDR3 in LGA 2011 to enhance bandwidth for data-intensive workloads. This evolution was driven by the burgeoning growth of cloud computing and virtualization in the early 2010s, where higher memory capacities and error-correcting code (ECC) support became essential for reliability in enterprise-like consumer applications.[14] Key milestones in the socket's development included its formal unveiling at the Intel Developer Forum (IDF) in September 2011, followed by the official launch on November 14, 2011, coinciding with the release of the Sandy Bridge-E processor series (Core i7-3000X models) and the X79 chipset for desktop platforms. Subsequent revisions extended the socket's lifecycle: LGA 2011-1 was introduced in 2013 alongside Ivy Bridge-EP processors (Xeon E5 v2 family) and the C600-series chipsets for servers, maintaining DDR3 support while optimizing for higher clock speeds and efficiency. In 2014, LGA 2011-3 debuted with Haswell-E processors and the X99 chipset, transitioning to DDR4 memory for improved performance in both HEDT and embedded systems, such as industrial and medical applications.[15][16][17][18] Support for the LGA 2011 family concluded with the Broadwell-E processors in mid-2016, marking the end of new CPU introductions after nearly five years of iterations. The socket was succeeded in 2017 by LGA 2066 for HEDT platforms (with Skylake-X processors) and LGA 3647 for enterprise servers, reflecting Intel's pivot to finer process nodes and expanded core counts. The platform's legacy includes pioneering consumer access to server-grade features, such as unbuffered ECC memory on X79 and X99 motherboards paired with compatible Xeon processors, which bolstered system stability for content creation and scientific computing. This contributed to Intel's unchallenged dominance in the HEDT market until AMD's Ryzen Threadripper launch in 2017 disrupted the segment with superior multi-threaded performance at competitive prices.[19][20][21][22]Design specifications
Physical characteristics
The LGA 2011 socket utilizes a Zero Insertion Force (ZIF) design, featuring a lever mechanism that allows the processor to be placed into the socket without applying force to the contacts, thereby minimizing wear during installation. This mechanism includes an Integrated Load Mechanism (ILM) with a stiffener plate and backplate assembly to distribute pressure evenly and protect the motherboard PCB from damage under load. The three-piece configuration—comprising the socket, ILM, and backplate—ensures reliable solder-joint integrity and supports dual actuation levers for maintaining processor planarity.[23][3] The socket accommodates 2011 contact lands arranged in a hexagonal grid array with a 1.016 mm (0.040 inch) pitch, spanning a 58 by 43 grid pattern with central depopulation for structural and thermal considerations. Alignment and keying are facilitated by triangle-shaped pin-1 indicators on the socket housing, load plate, and orientation posts, along with fiducial marks and notched corners on the processor package to prevent incorrect insertion and ensure precise orientation. This design supports compatibility with active cooling solutions rated for processors up to 150 W TDP in desktop applications, with provisions for higher thermal loads in server environments through appropriate heatsink mounting.[3][23][24] Installation involves opening the ZIF lever to expose the socket, aligning the processor's notched corners with the socket's keys, gently placing the processor into position, and then closing the lever to secure it via cam action that compresses the contacts. A thermal interface material, such as grease or pad, must be applied to the processor's integrated heat spreader (IHS) prior to mounting the cooling solution to facilitate efficient heat dissipation. The socket is constructed with high-temperature thermoplastic housing and high-strength copper alloy contacts for robustness.[25][23] Durability is specified for a minimum of 30 insertion and removal cycles, though proper handling is essential to avoid common issues such as bent contacts, which can occur if excessive force is applied during processor seating. Standoffs on the socket base establish a minimum height post-solder reflow, contributing to long-term mechanical stability.[23][26]Electrical and interface features
The LGA 2011 socket allocates its 2011 pins across various functions to support high-performance computing interfaces, with pins allocated to signal transmission, power and ground delivery for stable operation under high loads, and reserved for potential future expansions or manufacturing tests.[3] These allocations ensure efficient electrical connectivity, with power pins distributed to handle elevated current demands and minimize voltage droop during peak activity. The design incorporates pins for the QuickPath Interconnect (QPI), a point-to-point serial link protocol that facilitates multi-processor communication at speeds of 6.4 GT/s, 8.0 GT/s, or 9.6 GT/s, depending on the processor generation, enabling scalable server configurations.[4] Voltage specifications for the LGA 2011 family are managed dynamically through the Serial Voltage Identification (SVID) interface, allowing core supply voltages to range from 0.60 V to 1.35 V for efficient power scaling across idle and turbo states.[27] I/O voltages are set at 1.05 V for DDR3 memory interfaces in the original socket and 1.2 V for DDR4 in subsequent revisions, with overall power delivery supporting thermal design powers (TDP) up to 130 W for high-end desktop processors and exceeding 150 W for server variants to accommodate demanding workloads.[4] These parameters promote energy efficiency while maintaining compatibility with varying processor requirements. Memory interfaces in LGA 2011 sockets utilize a quad-channel architecture integrated into the processor, supporting DDR3 memory at speeds up to 1866 MT/s with maximum capacities of 64 GB in the original variant, and transitioning to DDR4 at up to 2400 MT/s with 128 GB support in later versions; error-correcting code (ECC) memory is standard for enhanced reliability in professional applications. For expansion, each socket provides 40 PCIe 3.0 lanes directly from the processor, enabling high-bandwidth connectivity for graphics and storage devices, while additional I/O standards such as USB 2.0/3.0 and SATA 6 Gb/s are handled through the platform chipset rather than dedicated socket pins. Notably, the socket lacks pins for integrated graphics processing, necessitating discrete GPU solutions for visual output. Thermal management is facilitated by an on-die Digital Thermal Sensor (DTS) that monitors core temperatures relative to the thermal control circuit (TCC) activation threshold, enabling dynamic frequency scaling and fan speed adjustments to prevent overheating and optimize performance under load.[3] This sensor-based approach allows precise control over power states, ensuring the socket's electrical integrity across extended operations.Socket variants
Original LGA 2011
The original LGA 2011 socket, codenamed Socket R, was introduced by Intel in November 2011 as part of the Sandy Bridge-E platform launch. This socket marked a significant evolution from its predecessor, LGA 1366, by increasing the pin count to 2011 from 1366 and introducing full quad-channel DDR3 memory support, enabling higher bandwidth for high-end desktop and server applications. The design emphasized enhanced I/O capabilities, with the CPU providing up to 40 PCIe 3.0 lanes directly. Backward compatibility with prior sockets like LGA 1366 was not possible due to the redesigned pinout and increased pin density. It exclusively supported Sandy Bridge-E processors for desktops (such as the Core i7-3960X) and Xeon E5 v1/v2 series for servers. These processors leveraged the socket's architecture for multi-core workloads, but the platform remained limited to DDR3 memory, lacking support for DDR4 found in later variants. Key limitations included reliance on DDR3, which capped memory speeds relative to subsequent generations, and variable PCIe lane allocation on early motherboards, often restricting full 40-lane utilization without BIOS updates. Additionally, the higher power draw of supported CPUs—up to 130W TDP for flagship models—necessitated robust cooling solutions, such as high-end air coolers or liquid cooling, to maintain stability under load. Adoption centered on the X79 chipset for high-end desktop (HEDT) systems and the C600 series for servers, powering early multi-GPU and content-creation builds. It gained popularity in first-generation HEDT configurations, exemplified by spacious cases like the Corsair 900D, which accommodated extensive cooling and expansion for enthusiasts.[28]LGA 2011-1
The LGA 2011-1, also known as Socket R2, was introduced in Q2 2013 as a mid-cycle revision to the original LGA 2011 socket, enabling support for updated processor generations while maintaining the overall 2011-pin land grid array (LGA) form factor. This revision is pin-compatible with later iterations within the LGA 2011-1 family but not with the original LGA 2011, due to changes in the integrated latch mechanism (ILM) keying and pin assignments that prevent cross-compatibility to avoid electrical mismatches.[26] Key modifications in the LGA 2011-1 include enhancements to the QuickPath Interconnect (QPI) for higher inter-processor bandwidth, reaching up to 9.6 GT/s in later implementations, and support for DDR3 memory (Xeon E7 v2) or DDR3/DDR4 (Xeon E7 v3). These updates facilitate greater scalability in multi-socket systems (up to 8 sockets) and better integration with high-speed peripherals.[29] The socket is compatible with Xeon E7 v2, v3, and v4 series for multi-socket server environments, and requires the C610 series chipsets to fully utilize its features. This compatibility ensures support for quad-channel (or more) memory configurations and advanced I/O capabilities.[30] Adoption of the LGA 2011-1 platform offered advantages such as the ability to handle higher thermal design powers (TDP) up to 165 W per processor, and lower latency in multi-socket configurations, which proved beneficial for compute-intensive workloads like virtualization and database processing. However, early implementations encountered challenges, including elevated DDR4 module pricing—often 2-3 times that of DDR3 equivalents—and occasional stability issues related to memory training and compatibility with initial chipset firmware.[30] The platform was later extended to support Broadwell-based processors, maintaining backward compatibility within the socket revision for continued relevance in enterprise environments.LGA 2011-3
The LGA 2011-3 socket, codenamed Socket R3, is the DDR4-enabled variant of the LGA 2011 family for high-end desktop and single/dual-socket server platforms. Introduced in 2014 alongside Intel's Haswell-E and Haswell-EP processors, it gained further prominence in Q1 2015 with the rollout of Broadwell-E and Broadwell-EP.[31] This variant targets high-performance applications, enabling deployment in enthusiast HEDT systems and scalable server configurations. Key features of LGA 2011-3 include retention of the 2011-pin land grid array (LGA) interface, with modifications to the pinout for DDR4 memory support and enhanced power delivery for processors with thermal design power (TDP) ratings from 55 W to 160 W. It supports DDR4 ECC and non-ECC memory in quad-channel configurations, providing reliable error correction for mission-critical tasks while increasing overall system bandwidth compared to DDR3 variants. The socket pairs with Haswell-E and Broadwell-E Core i7 processors for desktops, as well as the full Xeon E5 v3 (Haswell-EP) and v4 (Broadwell-EP) series for servers, leveraging the revised C610 chipset family (such as C612) or X99 for desktops for integrated I/O management.[32] Designed for workstations, high-end desktops, and 1-2 socket servers, LGA 2011-3 emphasizes high I/O density, including support for up to 40 PCIe 3.0 lanes and integrated 10GbE networking on compatible motherboards. This focus addresses the needs of demanding workloads requiring dense connectivity and efficient resource utilization, such as content creation, virtualization, or data analytics. As part of the broader Haswell and Broadwell microarchitecture families, it delivers high performance for compute-intensive scenarios.[33] Despite its advantages, LGA 2011-3 has inherent limitations, including the maximum of dual-socket support, which restricts scalability compared to multi-socket E7 platforms, and eventual obsolescence with the shift to newer architectures. These trade-offs balance performance, power, and cost for mainstream HEDT and server deployments.Chipsets
Desktop chipsets
The Intel X79 Express chipset, codenamed Patsburg, served as the primary platform controller hub (PCH) for the original LGA 2011 socket, launching in the fourth quarter of 2011 to support high-end desktop (HEDT) systems based on Sandy Bridge-E and Ivy Bridge-E processors.[34] It provided 8 PCIe 2.0 lanes directly from the PCH, enabling connectivity for peripherals and storage expansion, while integrating support for up to 14 USB 2.0 ports and 6 SATA ports (2 at 6 Gb/s and 4 at 3 Gb/s).[34] USB 3.0 functionality was incorporated on motherboards via additional controllers, such as those from ASMedia, to meet contemporary connectivity demands.[35] The chipset emphasized enthusiast features, including Intel Rapid Storage Technology (RST) for RAID configurations (0, 1, 5, 10) on SATA drives, and native overclocking support for unlocked "K" series processors through base clock (BCLK) adjustments.[35] It lacked integrated graphics, requiring discrete GPUs for visual output, and supported quad-channel DDR3 memory up to 64 GB across 8 DIMM slots on typical boards like the ASUS Rampage IV Extreme.[34] In 2014, Intel introduced the X99 chipset, codenamed Wellsburg, as a revised PCH for the LGA 2011-3 socket variant, targeting Haswell-E and Broadwell-E HEDT processors with a launch in the third quarter.[36] This platform advanced storage and connectivity with 10 SATA 6 Gb/s ports and native support for up to 6 USB 3.0 ports alongside 8 USB 2.0 ports, totaling 14 USB endpoints for enhanced data transfer speeds up to 5 Gbit/s on SuperSpeed ports.[37] It also enabled M.2 and NVMe SSD integration through PCIe lanes, facilitating faster boot times and application loading in consumer setups.[37] Like its predecessor, X99 included 8 PCIe 2.0 lanes from the PCH and RST 14 for RAID 0/1/5/10 arrays, with improved overclocking capabilities via integrated voltage regulation modules on motherboards to stabilize higher frequencies on "K" CPUs.[36] Designed for single-socket configurations without integrated graphics, it supported quad-channel DDR4 memory up to 128 GB on 8 DIMM slots, as seen in examples like the Gigabyte GA-X99-UD4.[36] Both chipsets catered to enthusiast and workstation users by prioritizing expandability and performance tuning for HEDT processors, evolving from DDR3 to DDR4 memory architectures while maintaining a focus on discrete GPU reliance and storage RAID options.[37]| Feature | X79 (Patsburg) | X99 (Wellsburg) |
|---|---|---|
| Launch Quarter | Q4 2011 | Q3 2014 |
| PCIe Lanes from PCH | 8 (Gen 2) | 8 (Gen 2) |
| SATA Ports (6 Gb/s) | 2 (plus 4 at 3 Gb/s) | 10 |
| USB Ports | 14 (USB 2.0; USB 3.0 via add-on) | 14 (6 USB 3.0 + 8 USB 2.0) |
| RAID Support | 0/1/5/10 via RST | 0/1/5/10 via RST 14 |
| Memory Support | Quad-channel DDR3 (up to 64 GB) | Quad-channel DDR4 (up to 128 GB) |
| Overclocking | BCLK for "K" CPUs | BCLK + VRM for "K" CPUs |
Server chipsets
The Intel C600 series chipset, released in March 2012, serves as the foundational server platform for LGA 2011 sockets, supporting Intel Xeon E5-2600 and E5-1600 series processors with DDR3 memory.[38] It enables configurations from single-socket to up to eight-socket systems through dual QuickPath Interconnect (QPI) links per processor, facilitating high-bandwidth inter-processor communication in multi-socket environments.[38] Key enterprise features include Reliability, Availability, and Serviceability (RAS) capabilities such as memory mirroring and hot-swap support for enhanced fault tolerance, along with Intel Trusted Execution Technology (TXT) for secure measured launches in virtualized setups.[38] Additionally, it incorporates IPMI 2.0 for remote management and optional 10 Gigabit Ethernet (10GbE) integration to meet data center networking demands.[38] The revised Intel C610 series chipset (codenamed Wellsburg), released in 2014, extends support to LGA 2011-1 and LGA 2011-3 variants, introducing DDR4 memory compatibility for improved bandwidth and efficiency in Xeon E5 v3 and v4 processors.[39] It expands I/O capabilities with up to 80 PCIe 3.0 lanes from the CPUs (40 per CPU) plus 8 PCIe 2.0 lanes from the PCH, configurable for multi-socket scaling, and adds SR-IOV support for efficient virtualization of network and storage resources.[39] Like its predecessor, the C610 emphasizes enterprise-grade RAS features, including advanced memory error correction and hot-plug components, while retaining Intel TXT for security and IPMI 2.0 for out-of-band management; it also supports 1- to 8-socket configurations for E5 and E7 series scalability.[39] Notable platform implementations include Supermicro's X9 series motherboards, such as the X9DR3-F and X9SRW-F, which leverage the C600 chipset for dual-socket LGA 2011 systems with extensive storage and networking options. In E7 configurations, these platforms can accommodate up to 3 TB of DDR3 registered memory, enabling large-scale database and virtualization workloads.[38] The primary distinction lies in memory and interface evolution: C600 is tailored for DDR3-based LGA 2011 systems, while C610 targets DDR4-enabled LGA 2011-1 and LGA 2011-3 for next-generation performance without altering core socket mechanics.[39]| Feature | Intel C600 Series (2012) | Intel C610 Series (2014) |
|---|---|---|
| Socket Compatibility | LGA 2011 (DDR3) | LGA 2011-1 (DDR3), LGA 2011-3 (DDR4) |
| Max Sockets | 8 (via dual QPI) | 8 (via QPI) |
| PCIe Lanes | 8x PCIe 2.0 (PCH) | Up to 80 total PCIe 3.0 (platform) |
| Key Enterprise Additions | IPMI 2.0, 10GbE options, RAS (mirroring/hot-swap), TXT | SR-IOV, expanded RAS/TXT, IPMI 2.0 |
| Max Memory Example (E7) | 3 TB DDR3 | N/A (focus on DDR4 for v3/v4) |
Compatible processors
High-end desktop processors
The high-end desktop (HEDT) processors for LGA 2011 sockets were part of Intel's Core i7 Extreme Edition lineup, designed for enthusiasts seeking maximum performance in consumer applications such as content creation and gaming. These processors, spanning multiple microarchitectures, offered unlocked multipliers for overclocking and supported quad-channel memory configurations to enhance bandwidth for memory-intensive workloads.[40] The inaugural Sandy Bridge-E series, launched in November 2011, introduced the Core i7-3960X as its flagship model. This 32 nm processor featured 6 cores and 12 threads via Hyper-Threading, a base clock of 3.3 GHz (turbo up to 3.9 GHz), 15 MB of L3 cache, and a 130 W TDP. It supported quad-channel DDR3-1600 memory and was compatible with the original LGA 2011 socket, paired with the X79 chipset for overclocking capabilities.[40] Succeeding it, the Ivy Bridge-E series arrived in September 2013 with the Core i7-4960X, built on a refined 22 nm process. Retaining the 6-core/12-thread configuration, it boosted the base clock to 3.6 GHz (turbo up to 4.0 GHz) while maintaining 15 MB L3 cache and 130 W TDP. The architecture delivered approximately 10% higher instructions per clock (IPC) compared to Sandy Bridge-E, improving efficiency in single- and multi-threaded tasks, alongside continued quad-channel DDR3 support on LGA 2011.[41] The Haswell-E lineup, released in August 2014, marked a shift to the LGA 2011-3 variant and introduced DDR4 memory support. The top-tier Core i7-5960X provided 8 cores and 16 threads, a 3.0 GHz base clock (turbo up to 3.5 GHz), 20 MB L3 cache, and 140 W TDP on a 22 nm process. It added AVX2 instructions for enhanced vector processing in applications like video encoding, while preserving unlocked overclocking and quad-channel memory (now DDR4-2133). Culminating the LGA 2011 era, Broadwell-E debuted in May 2016 with the Core i7-6950X as the ultimate HEDT offering on LGA 2011-3. This 14 nm processor scaled to 10 cores and 20 threads, with a 3.0 GHz base (turbo up to 3.5 GHz, or 4.0 GHz via Turbo Boost Max 3.0), 25 MB L3 cache, and 140 W TDP. It supported quad-channel DDR4-2400 and excelled in multi-threaded workloads such as 3D rendering, where its higher core count delivered substantial gains over predecessors—up to 40% faster in parallel tasks compared to the 6-core Ivy Bridge-E models.[42]| Processor | Release Year | Cores/Threads | Base/Turbo Clock (GHz) | L3 Cache | TDP (W) | Memory Support | Socket |
|---|---|---|---|---|---|---|---|
| Core i7-3960X | 2011 | 6/12 | 3.3/3.9 | 15 MB | 130 | Quad DDR3-1600 | LGA 2011 |
| Core i7-4960X | 2013 | 6/12 | 3.6/4.0 | 15 MB | 130 | Quad DDR3-1866 | LGA 2011 |
| Core i7-5960X | 2014 | 8/16 | 3.0/3.5 | 20 MB | 140 | Quad DDR4-2133 | LGA 2011-3 |
| Core i7-6950X | 2016 | 10/20 | 3.0/3.5 (4.0 Max) | 25 MB | 140 | Quad DDR4-2400 | LGA 2011-3 |