Pentium II Xeon

450 MHz Pentium II Xeon with 512 kB L2 cache: The cartridge cover has been removed.

The first Xeon-branded processor was the Pentium II Xeon (code-named "Drake"). It was released in 1998, replacing the Pentium Pro in Intel's high-end server lineup. The Pentium II Xeon was a "Deschutes" Pentium II (and shared the same product code: 80523) with a full-speed 512 kB (1 kB = 1024 B), 1 MB (1 MB = 1024 kB = 1024² B), or 2 MB L2 cache. The L2 cache was implemented with custom 512 kB SRAMs developed by Intel. The number of SRAMs depended on the amount of cache. A 512 kB configuration required one SRAM, a 1 MB configuration: two SRAMs, and a 2 MB configuration: four SRAMs on both sides of the PCB. Each SRAM was a 12.90 mm by 17.23 mm (222.21 mm²) die fabricated in a 0.35 µm four-layer metal CMOS process and packaged in a cavity-down wire-bonded land grid array (LGA).^[4] The additional cache required a larger module and thus the Pentium II Xeon used a larger slot, Slot 2. It was supported by the i440GX dual-processor workstation chipset and the i450NX quad- or octo-processor server chipset.

Pentium III Xeon

Back of a Pentium III Xeon with its cover set aside; there is a heatsink on the front side (underneath) of the circuit board.

Front of a Pentium III Xeon circuit board without its heatsink

Die shot of a Cascades Pentium III Xeon

In 1999, the Pentium II Xeon was replaced by the Pentium III Xeon. Reflecting the incremental changes from the Pentium II "Deschutes" core to the Pentium III "Katmai" core, the first Pentium III Xeon, named "Tanner", was just like its predecessor except for the addition of Streaming SIMD Extensions (SSE) and a few cache controller improvements. The product codes for Tanner mirrored that of Katmai; 80525.

The second version, named "Cascades", was based on the Pentium III "Coppermine" core. The "Cascades" Xeon used a 133 MT/s front side bus and relatively small 256 kB on-die L2 cache resulting in almost the same capabilities as the Slot 1 Coppermine processors, which were capable of dual-processor operation but not quad-processor or octa-processor operation.

To improve this situation, Intel released another version, officially also named "Cascades", but often referred to as "Cascades 2 MB". That came in two variants: with 1 MB or 2 MB of L2 cache. Its bus speed was fixed at 100 MT/s, though in practice the cache was able to offset this. The product code for Cascades mirrored that of Coppermine; 80526.

Xeon (DP) and Xeon MP (32-bit)

Gallatin

Gallatin

General information
Launched	March 2003
Discontinued	2004
CPUID code	0F7x
Product code	80537
Performance
Max. CPU clock rate	1.50 GHz to 3.20 GHz
FSB speeds	400 MT/s to 533 MT/s
Cache
L1 cache	8 kB + 12 kuOps trace cache
L2 cache	512 kB
L3 cache	1 MB, 2 MB, 4 MB
Architecture and classification
Application	DP and MP Server
Technology node	130 nm
Microarchitecture	NetBurst
Instruction set	x86
Physical specifications
Cores	1
Package(s)	Socket 603 Socket 604
Products, models, variants
Brand name(s)	Xeon

Main articles: List of Intel NetBurst-based Xeon microprocessors § "Gallatin" (130 nm), and § "Gallatin" MP (130 nm)

Subsequent to the Prestonia was the "Gallatin", which had an L3 cache of 1 MB or 2 MB. Its Xeon MP version, which succeeded Foster MP, was popular in servers. Later experience with the 130 nm process allowed Intel to create the Xeon MP branded Gallatin with 4 MB cache. The Xeon branded Prestonia and Gallatin were designated 80532, like Northwood.

Xeon (DP) and Xeon MP (64-bit)

Dual-Core Xeon

LV (ULV), "Sossaman"

Sossaman

General information
Launched	2006
Discontinued	2008
CPUID code	06Ex
Product code	80539
Performance
Max. CPU clock rate	1.667 GHz to 2.167 GHz
FSB speeds	667 MT/s
Cache
L2 cache	2 MB
Architecture and classification
Application	DP Server
Technology node	65 nm
Microarchitecture	Enhanced Pentium M
Instruction set	x86
Physical specifications
Cores	2
Package(s)	Socket M
Products, models, variants
Brand name(s)	Xeon

On March 14, 2006, Intel released a dual-core processor codenamed Sossaman and branded as Xeon LV (low-voltage). Subsequently, an ULV (ultra-low-voltage) version was released. The Sossaman was a low-/ultra-low-power and double-processor capable CPU (like AMD Quad FX), based on the "Yonah" processor, for ultradense non-consumer environment (i.e., targeted at the blade-server and embedded markets), and was rated at a thermal design power (TDP) of 31 W (LV: 1.66 GHz, 2 GHz and 2.16 GHz) and 15 W (ULV: 1.66 GHz).^[8] As such, it supported most of the same features as earlier Xeons: Virtualization Technology, 667 MT/s front side bus, and dual-core processing, but did not support 64-bit operations, so it could not run 64-bit server software, such as Microsoft Exchange Server 2007, and therefore was limited to 16 GB of memory. A planned successor, codenamed "Merom MP" was to be a drop-in upgrade to enable Sossaman-based servers to upgrade to 64-bit capability. However, this was abandoned in favour of low-voltage versions of the Woodcrest LV processor leaving the Sossaman at a dead-end with no upgrade path.

Dual-Core

5100-series "Woodcrest"

Main article: List of Intel Core-based Xeon microprocessors § "Woodcrest" (65 nm)

Woodcrest

General information
Launched	2006 (2006)
Discontinued	2009 (2009)
Marketed by	Intel
Designed by	Intel
Common manufacturer(s)	Intel
CPUID code	06Fx
Product code	80556
Performance
Max. CPU clock rate	1.60 GHz to 3.0 GHz
FSB speeds	1066 MT/s to 1333 MT/s
Cache
L1 cache	128 KB (64 KB (32 KB instruction + 32 KB data) x 2)
L2 cache	4 MB
Architecture and classification
Application	DP Server
Technology node	65nm
Microarchitecture	Core/Merom
Instruction set	x86-64
Physical specifications
Cores	2
Socket(s)	LGA 771
Products, models, variants
Brand name(s)	Xeon 51xx
Variant(s)	Clovertown Tigerton
History
Predecessor(s)	Dempsey
Successor(s)	Wolfdale-DP

On June 26, 2006, Intel released the dual-core CPU (Xeon branded 5100 series) codenamed Woodcrest (product code 80556); it was the first Intel Core/Merom microarchitecture processor to be launched on the market. It is a dual-processor server and workstation version of the Core 2 processor. Intel claimed that it provides an 80% boost in performance, while reducing power consumption by 20% relative to the 5000 series Dempsey.

Most models have a 1333 MT/s FSB, except for the 5110 and 5120, which have a 1066 MT/s FSB. The fastest processor (5160) operates at 3.0 GHz. All Woodcrest processors use the LGA 771 (Socket J) socket and all except two models have a TDP of 65 W. The 5160 has a TDP of 80 W and the 5148LV (2.33 GHz) has a TDP of 40 W. The previous generation Xeons had a TDP of 130 W. All models support Intel 64 (Intel's x86-64 implementation), the XD bit, and Virtualization Technology, with the Demand-based switching power management option only on Dual-Core Xeon 5140 or above. Woodcrest has 4 MB of shared L2 cache.

Model	Speed	L2 Cache	FSB	TDP
5110	1.60 GHz	4 MB	1066 MT/s	65 W
5120	1.83 GHz
5128				40 W
5130	2.0 GHz		1333 MT/s	65 W
5138	2.13 GHz		1066 MT/s	35 W
5140	2.33 GHz		1333 MT/s	65 W
5148				40 W
5150	2.66 GHz			65 W
5160	3.00 GHz			80 W

Quad-Core and Six-Core Xeon

5300-series "Clovertown"

Main article: List of Intel Core-based Xeon microprocessors § "Clovertown" (65 nm)

Clovertown

General information
Launched	2006
Discontinued	present
CPUID code	06Fx
Product code	80563
Performance
Max. CPU clock rate	1.60 GHz to 3.0 GHz
FSB speeds	1066 MT/s to 1333
Cache
L2 cache	2×4 MB
Architecture and classification
Application	DP Server
Technology node	65 nm
Microarchitecture	Core
Instruction set	x86
Physical specifications
Cores	4
Package(s)	LGA 771
Products, models, variants
Brand name(s)	Xeon 53xx

A quad-core (2×2) successor of the Woodcrest for DP segment, consisting of two dual-core Woodcrest chips in one package similarly to the dual-core Pentium D branded CPUs (two single-core chips) or the quad-core Kentsfield. All Clovertowns use the LGA 771 package. The Clovertown has been usually implemented with two Woodcrest dies on a multi-chip module, with 8 MB of L2 cache (4 MB per die). Like Woodcrest, lower models use a 1066 MT/s FSB, and higher models use a 1333 MT/s FSB. Intel released Clovertown, product code 80563, on November 14, 2006^[21] with models E5310, E5320, E5335, E5345, and X5355, ranging from 1.6 GHz to 2.66 GHz. All models support: MMX, SSE, SSE2, SSE3, SSSE3, Intel 64, XD bit (an NX bit implementation), Intel VT. The E and X designations are borrowed from Intel's Core 2 model numbering scheme; an ending of -0 implies a 1066 MT/s FSB, and an ending of -5 implies a 1333 MT/s FSB.^[20] All models have a TDP of 80 W with the exception of the X5355, which has a TDP of 120 W, and the X5365, which has a TDP of 150 W. A low-voltage version of Clovertown with a TDP of 50 W has a model numbers L5310, L5320 and L5335 (1.6 GHz, 1.86 GHz and 2.0 GHz respectively). The 3.0 GHz X5365 arrived in July 2007, and became available in the Apple Mac Pro^[22] on April 4, 2007.^[23][24] The X5365 performs up to around 38 GFLOPS in the LINPACK benchmark.^[25]

Model	Speed (GHz)	L2 Cache (MB)	FSB (MHz)	TDP (W)
E5310	1.60	2 × 4	1066	80
L5310				50
E5320	1.86			80
L5320				50
E5335	2.00		1333	80
L5335				50
E5345	2.33			80
X5355	2.66			120
X5365	3.00			150

3400-series "Lynnfield"

Xeon 3400-series processors based on Lynnfield are designed for entry-level servers compared to Bloomfield, which is designed for uniprocessor workstations. Like Bloomfield, they are quad-core single-package processors based on the Nehalem microarchitecture, but were introduced almost a year later, in September 2009. The same processors are marketed for mid-range to high-end desktops systems as Core i5 and Core i7. They have two integrated memory channels as well as PCI Express and Direct Media Interface (DMI) links, but no QuickPath Interconnect (QPI) interface.

3400-series "Clarkdale"

At low end of the 3400-series is not a Lynnfield but a Clarkdale processor, which is also used in the Core i3-500 and Core i5-600 processors as well as the Celeron G1000 and G6000 Pentium series. A single model was released in March 2010, the Xeon L3406. Compared to all other Clarkdale-based products, this one does not support integrated graphics, but has a much lower thermal design power of just 30 W. Compared to the Lynnfield-based Xeon 3400 models, it only offers two cores.

W3500-series "Bloomfield"

Bloomfield (or Nehalem-E) is the codename for the successor to the Xeon 3300 series, is based on the Nehalem microarchitecture and uses the same 45 nm manufacturing methods as Intel's Penryn. The first processor released with the Nehalem architecture is the high-end desktop Core i7, which was released in November 2008. This is the server version for single CPU systems. This is a single-socket Intel Xeon processor designed for uniprocessor workstations. The performance improvements over the previous Xeon 3300 series are based mainly on:

• Integrated memory controller supporting three memory channels of DDR3 UDIMM (Unbuffered) or RDIMM (Registered)
• A new point-to-point processor interconnect QuickPath, replacing the legacy front side bus
• Simultaneous multithreading by multiple cores and hyper-threading (2× per core).
• Turbo Boost, an overclocking technology that allows the CPU to run at a clock speed higher than the base speed as needed

5500-series "Gainestown"

Gainestown or Nehalem-EP (Efficient Performance), the successor to Wolfdale-DP, and Harpertown, is based on the Nehalem microarchitecture and uses the same 45 nm manufacturing methods. The first processor released with the Nehalem microarchitecture is the high-end desktop Core i7, which was released in November 2008. Server processors of the Xeon 55xx range were first supplied to testers in December 2008.^[33]

The performance improvements over Wolfdale-DP and Harpertown processors are based mainly on:

• Monolithic design for quad-core models
• Integrated memory controller supporting three memory channels of DDR3 memory with ECC support.
• A new point-to-point processor interconnect QuickPath, replacing the legacy front side bus. Gainestown has two QuickPath interfaces.
• Hyper-threading (2× per core, starting from 5518), that was already present in NetBurst-based processors
• Turbo Boost, an overclocking technology that allows the CPU to run at a clock speed higher than the base speed as needed

C3500/C5500-series "Jasper Forest"

Jasper Forest is a Nehalem-based embedded processor with PCI Express connections on-die, core counts from 1 to 4 cores and power envelopes from 23 to 85 watts.^[34]

The uni-processor version without QPI comes as LC35xx and EC35xx, while the dual-processor version is sold as LC55xx and EC55xx and uses QPI for communication between the processors. Both versions use a DMI link to communicate with the 3420 that is also used in the 3400-series Lynfield Xeon processors, but use an LGA 1366 package that is otherwise used for processors with QPI but no DMI or PCI Express links. The CPUID code of both Lynnfield and Jasper forest is 106Ex, i.e., family 6, model 30.

The Celeron P1053 belongs into the same family as the LC35xx series, but lacks some RAS features that are present in the Xeon version.

W3600/5600-series "Gulftown" & "Westmere-EP"

Gulftown and Westmere-EP, six-core 32 nm architecture Westmere-based processors, are the basis for the Xeon 36xx and 56xx series and the Core i7-980X. It launched in the first quarter of 2010. The 36xx-series follows the 35xx-series Bloomfield uni-processor model while the 56xx-series follows the 55xx-series Gainestown dual-processor model and both are socket compatible to their predecessors.

6500/7500-series "Beckton"

Beckton

Xeon E7530 (with and without the heat spreader)
General information
Launched	March 30, 2010 (2010-03-30)
Discontinued	Q4 2012
Marketed by	Intel
Designed by	Intel
Common manufacturer(s)	Intel
CPUID code	206Ex
Product code	80604
Performance
Max. CPU clock rate	1.733 GHz to 2.667 GHz
QPI speeds	6.4 GT/s
Cache
L2 cache	256 KB per core
L3 cache	Up to 24 MB
Architecture and classification
Application	DP/MP Server
Technology node	45 nm
Microarchitecture	Nehalem
Instruction set	x86
Physical specifications
Cores	4-8
Package(s)	LGA 1567
Products, models, variants
Brand name(s)	Xeon 65xx (DP) Xeon 75xx (MP)

Beckton or Nehalem-EX (EXpandable server market) is a Nehalem-based processor with up to eight cores and uses buffering inside the chipset to support up to 16 standard DDR3 DIMMS per CPU socket without requiring the use of FB-DIMMS.^[35] Unlike all previous Xeon MP processors, Nehalem-EX uses the new LGA 1567 (Socket LS) package, replacing the Socket 604 used in the previous models, up to Xeon 7400 "Dunnington". The 75xx models have four QuickPath interfaces, so it can be used in up-to eight-socket configurations, while the 65xx models are only for up to two sockets. Designed by the Digital Enterprise Group (DEG) Santa Clara and Hudson Design Teams, Beckton is manufactured on the P1266 (45 nm) technology. Its launch in March 2010 coincided with that of its direct competitor, AMD's Opteron 6xxx "Magny-Cours".^[36]

Most models limit the number of cores and QPI links as well as the L3 cache size in order to get a broader range of products out of the single chip design.

E7-x8xx-series "Westmere-EX"

Westmere-EX is the follow-on to Beckton/Nehalem-EX and the first Intel processor to have ten CPU cores. The microarchitecture is the same as in the six-core Gulftown/Westmere-EP processor, but it uses the LGA 1567 package like Beckton to support up to eight sockets.

Starting with Westmere-EX, the naming scheme has changed once again, with "E7-xxxx" now signifying the high-end line of Xeon processors using a package that supports larger than two-CPU configurations, formerly the 7xxx series. Similarly, the 3xxx uniprocessor and 5xxx dual-processor series turned into E3-xxxx and E5-xxxx, respectively, for later processors.

E3-12xx-series "Sandy Bridge"

The Xeon E3-12xx line of processors, introduced in April 2011, uses the Sandy Bridge chips that are also the base for the Core i3/i5/i7-2xxx and Celeron/Pentium Gxxx products using the same LGA 1155 socket, but with a different set of features disabled. Notably, the Xeon variants include support for ECC memory, VT-d and trusted execution that are not present on the consumer models, while only some Xeon E3 enable the integrated GPU that is present on Sandy Bridge. Like its Xeon 3400-series predecessors, the Xeon E3 only supports operation with a single CPU socket and is targeted at entry-level workstations and servers. The CPUID of this processor is 0206A7h, the product code is 80623.

E3-12xx v2-series "Ivy Bridge"

Xeon E3-12xx v2 is a minor update of the Sandy Bridge-based E3-12xx, using the 22 nm shrink, and providing slightly better performance while remaining backwards compatible. They were released in May 2012 and mirror the desktop Core i3/i5/i7-3xxx parts.

E5-14xx/24xx series "Sandy Bridge-EN" and E5-16xx/26xx/46xx-series "Sandy Bridge-EP"

The Xeon E5-16xx processors follow the previous Xeon 3500/3600-series products as the high-end single-socket platform, using the LGA 2011 package introduced with this processor. They share the Sandy Bridge-E platform with the single-socket Core i7-38xx and i7-39xx processors. The CPU chips have no integrated GPU but eight CPU cores, some of which are disabled in the entry-level products. The Xeon E5-26xx line has the same features but also enables multi-socket operation like the earlier Xeon 5000-series and Xeon 7000-series processors.

E5-14xx v2/24xx v2 series "Ivy Bridge-EN" and E5-16xx v2/26xx v2/46xx v2 series "Ivy Bridge-EP"

The Xeon E5 v2 line was an update, released in September 2013 to replace the original Xeon E5 processors with a variant based on the Ivy Bridge shrink. The maximum number of CPU cores was raised to 12 per processor module and the total L3 cache was upped to 30 MB.^[37][38] The consumer version of the Xeon E5-16xx v2 processor is the Core i7-48xx and 49xx.

E7-28xx v2/48xx v2/88xx v2 series "Ivy Bridge-EX"

The Xeon E7 v2 line was an update, released in February 2014 to replace the original Xeon E7 processors with a variant based on the Ivy Bridge shrink. There was no Sandy Bridge version of these processors but rather a Westmere version.

E3-12xx v3 series "Haswell-WS"

Intel Xeon E3-1241 v3 CPU, sitting atop the inside part of its retail box that contains an OEM fan-cooled heatsink

Intel Xeon E3-1220 v3 CPU, pin side

Introduced in May 2013, Xeon E3-12xx v3 is the first Xeon series based on the Haswell microarchitecture. It uses the new LGA 1150 socket, which was introduced with the desktop Core i5/i7 Haswell processors, incompatible with the LGA 1155 that was used in Xeon E3 and E3 v2. As before, the main difference between the desktop and server versions is added support for ECC memory in the Xeon-branded parts. The main benefit of the new microarchitecture is better power efficiency.

E5-16xx/26xx v3 series "Haswell-EP"

Intel Xeon E5-1650 v3 CPU; its retail box contains no OEM heatsink.

Introduced in September 2014, Xeon E5-16xx v3 and Xeon E5-26xx v3 series use the new LGA 2011-v3 socket, which is incompatible with the LGA 2011 socket used by earlier Xeon E5 and E5 v2 generations based on Sandy Bridge and Ivy Bridge microarchitectures. Some of the main benefits of this generation, compared to the previous one, are improved power efficiency, higher core counts, and bigger last level caches (LLCs). Following the already used nomenclature, Xeon E5-26xx v3 series allows dual-socket operation.

One of the new features of this generation is that Xeon E5 v3 models with more than 10 cores support cluster on die (COD) operation mode, allowing CPU's multiple columns of cores and LLC slices to be logically divided into what is presented as two non-uniform memory access (NUMA) CPUs to the operating system. By keeping data and instructions local to the "partition" of CPU which is processing them, thus decreasing the LLC access latency, COD brings performance improvements to NUMA-aware operating systems and applications.^[39]

E7-48xx/88xx v3 series "Haswell-EX"

Introduced in May 2015, Xeon E7-48xx v3 and Xeon E7-88xx v3 series provide higher core counts, higher per-core performance and improved reliability features, compared to the previous Xeon E7 v2 generation. Following the usual SKU nomenclature, Xeon E7-48xx v3 and E7-88xx v3 series allow multi-socket operation, supporting up to quad- and eight-socket configurations, respectively.^[40][41] These processors use the LGA 2011 (R1) socket.^[42]

Xeon E7-48xx v3 and E7-88xx v3 series contain a quad-channel integrated memory controller (IMC), supporting both DDR3 and DDR4 LRDIMM or RDIMM memory modules through the use of Jordan Creek (DDR3) or Jordan Creek 2 (DDR4) memory buffer chips. Both versions of the memory buffer chip connect to the processor using version 2.0 of the Intel Scalable Memory Interconnect (SMI) interface, while supporting lockstep memory layouts for improved reliability. Up to four memory buffer chips can be connected to a processor, with up to six DIMM slots supported per each memory buffer chip.^[40][41]

Xeon E7-48xx v3 and E7-88xx v3 series also contain functional bug-free support for Transactional Synchronization Extensions (TSX), which was disabled via a microcode update in August 2014 for Haswell-E, Haswell-WS (E3-12xx v3) and Haswell-EP (E5-16xx/26xx v3) models, due to a bug that was discovered in the TSX implementation.^{[40][41][43][44][45][46]}

E3-12xx v4 series "Broadwell-H"

Introduced in June 2015, Xeon E3-12xx v4 is the first Xeon series based on the Broadwell microarchitecture. It uses LGA 1150 socket, which was introduced with the desktop Core i5/i7 Haswell processors. As before, the main difference between the desktop and server versions is added support for ECC memory in the Xeon-branded parts. The main benefit of the new microarchitecture is the new lithography process, which results in better power efficiency.

E3-12xx v5 series "Skylake-S"

Introduced in October 2015, Xeon E3-12xx v5 is the first Xeon series based on the Skylake microarchitecture. It uses new LGA 1151 socket, which was introduced with the desktop Core i5/i7 Skylake processors. Although it uses the same socket as consumer processors, it is limited to the C200 server chipset series and will not work with consumer chipsets like Z170. As before, the main difference between the desktop and server versions is added support for ECC memory in the Xeon-branded parts.

1st generation Xeon Scalable "Skylake-SP"

E3-12xx v6 series

Introduced in January 2017, Xeon E3-12xx v6 is the first Xeon series based on the Kaby Lake microarchitecture. It uses the same LGA 1151 socket, which was introduced with the desktop Core i5/i7 Kaby Lake processors. As before, the main difference between the desktop and server versions is added support for ECC memory and improved energy efficiency in the Xeon-branded parts.

Coffee Lake-E (Server/Workstation)

Coffee Lake-E Refresh (Server/Workstation)

Variants

• Server: Cascade Lake-SP (Scalable Performance; meaning multi physical processors configuration), Cascade Lake-AP (Advanced Performance)
• Workstation: Cascade Lake-W
• Enthusiast: Cascade Lake-X

Features