LGA 771

Socket J (LGA 771)
Release date	May 16, 2006; 18 years ago
Designed by	Intel
Manufactured by	Intel
Type	Land Grid Array (LGA)
Chip form factors	Flip chip land grid array
Contacts	771
FSB protocol	AGTL+
FSB frequency	667 MT/s, 1066 MT/s, 1333 MT/s, 1600 MT/s
Voltage range	Varies (1,3625V max)
Processor dimensions	37.5 mm x 37.5 mm
Processors	Intel Celeron 445; Intel Core 2 Duo E6x05; Intel Dual-Core Xeon E/X/L 50xx–52xx; Intel Quad-Core Xeon X 33xx; Intel Quad-Core Xeon E/X/L 53xx–54xx; Intel Core 2 Extreme QX9775
Predecessor	Socket 604
Variant	LGA 775 (Socket T)
Successor	LGA 1366
Memory support	DDR2, DDR3
	This article is part of the CPU socket series

LGA 771, also known as Socket J, is a CPU interface introduced by Intel in 2006.^[1] It is used in Intel Core microarchitecture and NetBurst microarchitecture (Dempsey) based DP-capable server processors, the Dual-Core Xeon is codenamed Dempsey, Woodcrest, and Wolfdale and the Quad-Core processors Clovertown, Harpertown, and Yorkfield-CL. It is also used for the Core 2 Extreme QX9775, and blade servers designated under Conroe-CL.

It was succeeded by LGA 1366 for the Nehalem-based Xeon processors.

Technical specifications

An Xeon E5450 modified to fit in LGA 775 motherboards.

As its name implies, it is a land grid array with 771 contacts. The word "socket" in this instance is a misnomer, as the processor interface has no pin holes. Instead, it has 771 protruding lands which touch contact points on the underside of the microprocessor.

The "J" in "Socket J" refers to the now-canceled processor codenamed "Jayhawk", which was expected to debut alongside this interface. It is intended as a successor to Socket 604 and takes much of its design from LGA 775 and is almost pin compatible with LGA 775.

Compared to LGA 775 CPUs, LGA 771 CPUs are rotated 90 degrees and have two pins swapped. Small adapters developed by Chinese computer DIY enthusiasts are available to allow LGA 771 CPUs to be installed in LGA 775 motherboards, if the BIOS microcode supports them (but it is also possible to add supporting microcode manually).^[2] This also allows for overclocking of Xeon (LGA 771) processors when used in the correct (LGA 775) motherboards. Some overclockers have managed quite substantial overclocks such as 4.023GHz on a Xeon X5492 for a total overclock of just over 18%.^[3]

Single core processors

Name	Cores	Frequency	L2 Cache	TDP	FSB	Release Date	Price
Xeon 3000 series
Xeon L3014	1	2.40 GHz	3 MB	30W	1066	Q1 2008	OEM
Celeron 400 series
Celeron 445	1	1.87 GHz	512 KB	65W	1066		OEM

Dual core processors

Hyper-threading supported only on 50xx series processors(codenamed Dempsey)

Name	Cores	Frequency	L2 Cache	TDP	FSB	Release date	Price
Xeon 5000 series
Xeon 5030	2	2.66 GHz	2*2 MB	95W	667
Xeon 5040		2.83 GHz
Xeon 5050		3.00 GHz
Xeon 5060		3.20 GHz		130W	1066
Xeon 5063		3.20 GHz		95W
Xeon 5070		3.46 GHz		130W
Xeon 5080		3.73 GHz		130W
Xeon 3100 series
Xeon E3113	2	3.00 GHz	6 MB	65W	1333	Q3 2008	OEM
Xeon 5100 series
Xeon 5110	2	1.60 GHz	4 MB	65W	1066
Xeon 5120		1.86 GHz			1066
Xeon 5130		2.00 GHz			1333	Q2 2006
Xeon 5140		2.33 GHz
Xeon LV 5148		2.33 GHz		40W
Xeon 5150		2.66 GHz		65W
Xeon 5160		3.00 GHz		80W
Xeon 5200 series
Xeon E5205	2	1.86 GHz	6 MB	65W	1066
Xeon E5220	2	2.33 GHz	6 MB	65W	1333
Xeon L5215	2	1.86 GHz	6 MB	20W	1066
Xeon L5240	2	3.00 GHz	6 MB	40W	1333
Xeon X5260	2	3.33 GHz	6 MB	80W	1333	Q4 2007
Xeon X5270		3.50 GHz			1333	Q3 2008
Xeon X5272		3.40 GHz			1600	Q4 2007

Intel Xeon 5140 processor. Compatible with LGA 771 motherboards. It has two cores at 2.33 GHz, 4 MB of L2 cache, an FSB speed of 1333 MT/s and a TDP of 65 W.^[4]

Quad core processors

Name	Cores	Frequency	L2 Cache	TDP	FSB	Release date	Price
Xeon 3300 Series
Xeon X3323	4	2.50 GHz	6 MB	80W	1333	Q1 2008	OEM
Xeon X3353		2.67 GHz	12 MB
Xeon X3363		2.83 GHz	12 MB
Xeon 5300 series
Xeon E5310	4	1.60 GHz	8 MB	80W	1066	Q4 2006
Xeon E5320		1.86 GHz			1066	Q4 2006
Xeon E5335		2.00 GHz			1333	Q1 2007
Xeon E5345		2.33 GHz			1333	Q1 2007
Xeon L5310	4	1.60 GHz	8 MB	50W	1066	Q1 2007
Xeon L5318		1.60 GHz		40W
Xeon L5320		1.86 GHz		50W
Xeon L5335		2.00 GHz		50W	1333	Q3 2007
Xeon X5355	4	2.66 GHz	8 MB	120W	1333	Q4 2006
Xeon X5365	4	3.00 GHz	8 MB	150W	1333	Q3 2007
Xeon 5400 series
Xeon E5405	4	2.00 GHz	12 MB	80W	1333	Q4 2007
Xeon E5410		2.33 GHz
Xeon E5420		2.50 GHz
Xeon E5430		2.66 GHz
Xeon E5440		2.83 GHz				Q1 2008
Xeon E5450		3.00 GHz				Q4 2007
Xeon E5462		2.80 GHz			1600
Xeon E5472		3.00 GHz			1600
Xeon L5408^[5]	4	2.13 GHz	12 MB	40W	1066	Q1 2008
Xeon L5410		2.33 GHz		50W	1333
Xeon L5420		2.50 GHz
Xeon L5430		2.66 GHz				Q3 2008
Xeon X5450	4	3.00 GHz	12 MB	120W	1333	Q4 2007
Xeon X5460		3.16 GHz				Q4 2007
Xeon X5470		3.33 GHz				Q3 2008
Xeon X5472		3.00 GHz			1600	Q4 2007
Xeon X5482		3.20 GHz		150W		Q4 2007
Xeon X5492		3.40 GHz		150W		Q3 2008
Core 2 Extreme QX9000 series
QX9775	4	3.20 GHz	12 MB	150W	1600	Q1 2008

References

^ "Intel® Socket Test Technology for LGA771". Intel. Retrieved June 29, 2016.
^ omega552003 (August 29, 2024). "[How To] Using a LGA 771 Xeon in a LGA 775 motherboard AKA 771 mod". linustechtips.com. Retrieved August 29, 2024.{{cite web}}: CS1 maint: numeric names: authors list (link)
^ "Intel Xeon X5492 @ HWBOT". HWBOT. Retrieved November 30, 2022.
^ "Intel® Xeon® Processor 5140 (4M Cache, 2.33 GHz, 1333 MHz FSB) Specifications". Retrieved July 28, 2016.
^ "Intel® Xeon® Processor L5408 (12M Cache, 2.13 GHz, 1066 MHz FSB) Product Specifications". Intel® ARK (Product Specs). Retrieved September 9, 2017.

[1] "Intel® Socket Test Technology for LGA771". Intel. Retrieved June 29, 2016.

[2] 552003 (August 29, 2024). "[How To] Using a LGA 771 Xeon in a LGA 775 motherboard AKA 771 mod". linustechtips.com. Retrieved August 29, 2024.{{cite web}}: CS1 maint: numeric names: authors list (link)

[3] "Intel Xeon X5492 @ HWBOT". HWBOT. Retrieved November 30, 2022.

[4] "Intel® Xeon® Processor 5140 (4M Cache, 2.33 GHz, 1333 MHz FSB) Specifications". Retrieved July 28, 2016.

[5] "Intel® Xeon® Processor L5408 (12M Cache, 2.13 GHz, 1066 MHz FSB) Product Specifications". Intel® ARK (Product Specs). Retrieved September 9, 2017.

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