Socket M socket: CPUs, chipsets and cooler fit

Socket M, printed mPGA478MT, is the Intel 478-contact PGA socket for 2006 mobile Core processors. It carries Core Solo Yonah single cores, Core Duo Yonah dual cores, and the first mobile Core 2 Duo Merom dual cores in Micro-FCPGA packages that drop into a Zero Insertion Force lever socket. Intel introduced it in 2006 as the successor to Socket 479 for the Napa platform with the 945PM and 945GM chipsets.

Quick facts

MakerIntel
Package typePGA
Contacts478
Package sizen/a
Introduced2006
StatusLegacy
MemoryDDR2 in two channels through the board chipset
PCIe from the CPUFront side bus 533 to 800 MT/s to the chipset; expansion from the mobile chipset
Cooler mounting holesBoard specific (laptop heatsink)
ReplacesSocket 479
Replaced bySocket P

Overview

The interface matters because it holds the socketed standard voltage parts of this batch, while soldered low voltage cousins with the same silicon stay on Socket 479. A Core Solo T1200 runs one Yonah core at 1.5 GHz with 2 MB of shared L2 cache inside a 27 W envelope, while a Core Duo T2300 runs two Yonah cores at 1.66 GHz with the same 2 MB cache at 31 W. Early Merom parts such as the Core 2 Duo T5200 at 1.6 GHz and the T7200 at 2 GHz add 64-bit support with 2 MB or 4 MB of L2 cache at 34 W on a 533 or 667 MT/s front side bus.

Memory is DDR2 in two channels through the board chipset, commonly DDR2-667 on Napa boards. Cooling uses notebook vendor heat pipe parts for the exact chassis, since retail desktop towers do not mount to mobile sockets. The successor Socket P arrived in 2007 with an 800 MT/s bus for Santa Rosa, so a move beyond Merom on Socket M means a board change.

Processor generations

CodenameMarketing nameYearsNotes
YonahCore Solo and Core Duo Yonah2006 to 200765 nm single and dual core parts with 2 MB of shared L2 cache, from the 1.5 GHz Core Solo T1200 at 27 W to the 2.33 GHz Core Duo T2700 at 31 W in 2006.
MeromCore 2 Duo Merom2006 to 200765 nm dual core parts with 2 MB or 4 MB of L2 cache and 64-bit support, from the 1.6 GHz T5200 at 34 W to the 2.17 GHz T7400 at 34 W in 2006.

Who Socket M serves

Socket M serves socketed Napa notebooks from 2006 where the CPU can be removed with the lever arm. Buyers chose a Core Solo for single thread office work, a Core Duo T2300 to T2700 for dual core multitasking at 31 W, or a Merom T5200 to T7400 for 64-bit support with larger cache. Each chip needs a board whose BIOS lists the exact sSpec stepping, since Napa BIOS revisions added Merom support after launch.

Soldered ULV and LV Yonah parts such as the U1300 at 5.5 W and the L2400 at 15 W do not belong here even though they share the Yonah name. Those Micro-FCBGA parts are soldered to the board and live under Socket 479. When a SKU exists in both a socketed Micro-FCPGA package and a soldered Micro-FCBGA package, this site lists it under Socket M and notes the soldered option in the CPU prose.

Memory and cooling

Memory on Socket M is DDR2 through the 945PM, 945GM, PM965, or GM965 board chipset in two channels. The chipset sets the speed and the slot count, so a 667 MT/s FSB chip pairs with DDR2-667 where the board supports it. A move to DDR3 means a move to a newer mobile platform with a new board.

The front side bus carries CPU traffic at 533 MT/s on early Yonah boards and 667 MT/s on later Yonah and Merom boards, with select 800 MT/s combinations on PM965 and GM965. No PCIe lanes come from the CPU itself. Cooling is a vendor heat pipe assembly for the 27 W to 34 W envelope, and paste or pad replacement follows the notebook service manual for the exact model.

CPUs on Socket M

18 processor pages in the database, newest first.

ProcessorCores / threadsBase / boostTDPLaunched
Intel Core 2 Duo T7600G2 / 22.33 GHz35 WDec 2006
Intel Core 2 Duo T52002 / 21.6 GHz34 WOct 2006
Intel Core 2 Duo T55002 / 21.67 GHz34 WAug 2006
Intel Core 2 Duo T56002 / 21.83 GHz34 WAug 2006
Intel Core 2 Duo T72002 / 22.0 GHz34 WAug 2006
Intel Core 2 Duo T74002 / 22.17 GHz34 WAug 2006
Intel Core 2 Duo T76002 / 22.33 GHz34 WJul 2006
Intel Core Solo T12001 / 11.5 GHz27 WJul 2006
Intel Core Solo T13501 / 11.87 GHz31 WJul 2006
Intel Core Duo T27002 / 22.33 GHz31 WJun 2006
Intel Core Duo T20502 / 21.6 GHz31 WMay 2006
Intel Core Duo T22502 / 21.73 GHz31 WMay 2006
Intel Core Solo T14001 / 11.83 GHz27 WMay 2006
Intel Core Duo T23002 / 21.66 GHz31 WJan 2006
Intel Core Duo T24002 / 21.83 GHz31 WJan 2006
Intel Core Duo T25002 / 22.0 GHz31 WJan 2006
Intel Core Duo T26002 / 22.17 GHz31 WJan 2006
Intel Core Solo T13001 / 11.66 GHz27 WJan 2006

Frequently asked questions

Which processors fit Socket M?

Socketed Core Solo T1200 to T1400, Core Duo T2250 to T2700, and Core 2 Duo T5200 to T7400 in Micro-FCPGA packages. Soldered ULV and LV Yonah parts with the same silicon live under Socket 479 instead.

Is Socket M the same as Socket 479?

No. Socket M has 478 contacts in the mPGA478MT layout while Socket 479 in its Pentium M version uses a different pin placement, and the two are not electrically compatible. A Socket M chip fits loosely in some Socket 479 boards but will not run, and forcing it can damage pins.

What memory does Socket M use?

DDR2 in two channels through the board chipset, commonly DDR2-667 SO-DIMMs on 945PM and 945GM boards. The board fixes the slots and the maximum capacity, so check the notebook vendor list.

How many PCIe lanes does Socket M provide?

No PCIe lanes come from these CPUs. A front side bus at 533 to 800 MT/s ties the CPU to the mobile chipset, while graphics and expansion slots hang off the chipset.

Sources and verification

  1. Socket M (Wikipedia)
  2. List of Intel Core mobile processors (Wikipedia)
  3. Yonah (microprocessor) (Wikipedia)

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