Intel Xeon L5639 socket: LGA 1366

The Intel Xeon L5639 uses the LGA 1366 socket. It is a 60 W six core Westmere-EP server part at 2.13 GHz with turbo to 2.67 GHz and ECC memory.

Socket
LGA 1366
Launched
February 2011
Cores and threads
6 and 12
Base power
60 W
Codename
Westmere-EP
Segment
Server
Clocks
2.13 / 2.67 GHz

Intel Xeon L5639 specifications

Cores6
Threads12
Core architectureWestmere-EP cores on 32 nm
Clocks2.13 GHz base, 2.67 GHz turbo
Cache12 MB Intel Smart Cache (L3)
Processor base power (TDP)60 W
Manufacturing process32 nm
Memory supportDDR3-1333, three channels, ECC supported
QPI links2 links, 5.86 GT/s
PCI ExpressPCIe 2.0
Integrated graphicsNone (server part)
MultiplierLocked
ECC memorySupported
PackageFCLGA1366

Motherboard and chipset compatibility

Intel Xeon L5639 needs a motherboard with a LGA 1366 socket. The table shows which chipset series accept it.

SeriesChipsetsSupport
5500 and 5520 server5500, 5520Works out of the box

Board makers publish a CPU support list for every model. Check it for your exact board before buying. Chipset details for LGA 1366.

LGA 1366 at a glance

TypeLGA, 1,366 contacts
Package sizen/a
Introduced2008
MemoryDDR3 triple channel, up to 24 GB on desktop boards
Cooler mounting holes80 × 80 mm

Read the full LGA 1366 socket guide

What the Xeon L5639 is

Intel Xeon L5639 is a six core Westmere-EP server processor that Intel released in February 2011 for single and dual socket boards. It runs at 2.133 GHz base with turbo to 2.667 GHz and includes Hyper-Threading, so 6 cores give 12 threads. Cache is 12 MB Intel Smart Cache. Power is 60 W on a 32 nm process with 1,170 million transistors on a 239 mm2 die.

The L prefix marks low power for dense racks and quiet workstations. Up to two L5639 CPUs work together over QuickPath links. The 60 W envelope allows compact cooling with server airflow.

There is no integrated graphics on this die. Memory runs in three DDR3 channels at up to 1333 MT/s with ECC. The chip launched on February 14, 2011 as an OEM part.

Socket and motherboard compatibility

The Xeon L5639 fits LGA 1366 in FCLGA1366 form. Single and dual socket server boards with 5500 and 5520 chipsets carry it. The board BIOS must list the exact L5639 string.

QuickPath links run at 2 by 5.86 GT/s between sockets. A board that lists Xeon 56xx strings is the safe choice for dual socket builds.

Memory, PCIe and cooling

Memory support is DDR3-1333, three channels, with ECC for mission critical work. Three matched modules per socket give 32 GB/s bandwidth. Capacity follows the board design.

PCI Express is revision 2.0 for server graphics and storage cards. Dual socket boards split lanes per the board manual.

Cooling uses 60 W server heatsinks on the 80 by 80 mm pattern with front to back airflow. Low power keeps fan speeds down in dense racks.

Upgrade paths

On LGA 1366 the L5639 can move to the L5645 for higher clocks at the same 60 W on the same board. Memory and storage carry over where the board lists both strings. A same socket low power reference is the L5638 class.

A platform move to LGA 2011 servers needs new boards and DDR3 RDIMMs in fours. Keep the L5639 board for efficient lab duty.

Frequently asked questions

What socket does the Intel Xeon L5639 use?

It uses LGA 1366 on single and dual socket server boards.

What does the L prefix mean on the Xeon L5639?

The L prefix marks low power at 60 W. Standard X5600 parts run at 95 W.

What memory does the Xeon L5639 use?

DDR3-1333 in three channels with ECC.

Can two Xeon L5639 parts work together?

Yes, up to two CPUs over QuickPath links.

Sources and verification

  1. Intel Xeon L5639 Specs (TechPowerUp, 2.133 GHz, turbo 2.667 GHz, ECC, Feb 2011)
  2. Westmere-EP L5639 2.13 GHz 60W Feb 2011 OEM (Simple Xeon list)

Facts last checked against these sources on . Page last edited on .