Socket 479 / Socket mPGA479M

Socket 479, also called mPGA479M, was introduced in 2001 as a socket for mobile Pentium III-M microprocessors, and, eventually, for mobile Celeron processors with Coppermine-T and Tualatin cores. The Pentium III-M CPUs were manufactured 478-pin package, but the socket itself had 479 pin holes, which made it easier for Intel to re-use the socket for other generations of microprocessors. Over the course of the next 5 years Intel introduced two other generations of mobile microprocessors that utilized the same socket, but were not compatible with each other or with Pentium III-M motherboards. Even more, socket 478 (Pentium 4 and mobile Pentium 4) and socket P (Core 2 Duo Mobile) processors could physically fit into socket 479, but were not electrically compatible with it. All these different families were manufactured in three different types of 478-pin package. The packages differed between themselves only by location of one pin, and, having one extra pin hole, it was sufficient for the socket to accommodate all three 478-pin package types. Below is the table that summarizes all families that can fit into the socket mPGA479M, but are not electrically compatible with each other:

CPU familiesMicroarchitectureSocketNotes
Mobile Celeron
Pentium III-M
P6Socket 479 or
Socket mPGA478A is physically the same as socket M
Pentium 4
Mobile Celeron
Mobile Pentium 4-M
Mobile Pentium 4
NetBurstmPGA478B (socket 478)Fits into, but doesn't work in socket 479
Celeron M 300 series
Pentium M
MobileSocket 479 or
mPGA478C socket was used in small number of Celeron M / Pentium M motherboards
Core Solo
Core Duo
Celeron M 400 and 500 series
Pentium Dual-Core Mobile
Core 2 Duo Mobile
Socket 479 or
Socket M
Socket M is physically the same as socket mPGA478A
Celeron M 500 series
Mobile Pentium Dual-Core
Core 2 Duo Mobile
Core 2 Duo Quad
Core 2 Duo Extreme
CoreSocket PFits into, but doesn't work in socket 479

The socket 479 works with mobile processors with frequencies up to 2333 MHz and FSB frequencies up to 667 MHz.

Socket 479 - top viewSocket 479 - view with CPUSocket 479 - side view

The socket has 479 pin holes arranged as 26 x 26 grid with 14 x 14 section removed from the center of the grid. The socket has 1 corner pin hole plugged. Socket dimensions are 3.6 cm x 4.4 cm or 1.42" x 1.73".

Supported processors

All processors in the table below will physically fit into the socket, but not all of them are supported by all motherboards. If you're upgrading an old computer system please make sure that the CPU is compatible with your motherboard. Please see "Upgrading socket 479 motherboards" section below for information on how to determine what microprocessors can be supported by your motherboard.

There are no AMD processors compatible with this socket.

Compatible sockets

Socket mPGA478C (for Celeron M 300 series and Pentium M motherboards)
Socket M (for motherboards supporting Core Solo, Core Duo, Celeron M 400 and 500 series, Pentium Dual-Core Mobile and Core 2 Duo Mobile)

Compatible package types

478-pin micro FC-PGA

Upgrading socket 479 motherboards

Because it's easy to put electrically-incompatible CPU into the socket 479 and thus damage the CPU and/or the motherboard, it is very important that you verify processor compatibility before buying and installing it. Depending on the type of motherboard you have, your upgrade choices are:

  • Mobile Celeron / Pentium III-M motherboard: your best upgrade option is a Mobile Pentium III-M 1333. You cannot upgrade to any other mobile processors.
  • Celeron M 300 series or Pentium M:
    • If your motherboard supports 533 MHz FSB then the fastest upgrade option is a Pentium M 780. If the Pentium M 780 seems too expensive or difficult to find then consider upgrading to Pentium 770.
    • If your motherboard supports only 400 MHz FSB then the fastest upgrade option is a Pentium M 765. If the Pentium M 765 seems too expensive or difficult to find then consider upgrading to Pentium 755.
    You cannot upgrade to Core Solo, Core Duo, Celeron M 400 / 500 series, Pentium Dual-Core Mobile or Core 2 Duo Mobile processors.
  • Celeron M 400 or 500 series, Core Solo, Core Duo, Pentium Dual-Core Mobile or Core 2 Duo Mobile (all socket M processors):
    • The best upgrade option is a Core 2 Duo Mobile T7600 or T7600G. The T7600G has unlocked clock multiplier and can be overclocked, but it's very difficult to find.
    • If the T7600 / T7600G is too expensive for you then consider upgrading to slower Core 2 Duo Mobile processors.
    • If you motherboard doesn't support Core 2 Duo Mobile CPUs then your best upgrade option is a Core Duo T2700.

To determine what processors are supported you'll need to:

  • Determine manufacturer and model of your motherboard,
  • Search on manufacturer's website for the motherboard model.

To determine upgrade options for brand name computers (like Dell or HP) try to search for computer model on computer manufacturer website.

For upgrade information for ABIT, ASRock, ASUS, DFI, ECS, Gigabyte Technology, Jetway, MSI, PC Chips motherboards please check CPU-Upgrade motherboard database.


There are 8 comments posted
1 comment was recently rejected. Please see a reason here.


2009-09-25 11:59:09
Posted by: micky

The only place where I can found the information for updating my laptop (toshiba satellite A100-534, cleron m 370 and now pentium m 740 )

Very interresting web site, thanks.

Upgrade of Socket 479mPGA from Pentium 'M' to Pentium '4'

2010-08-02 11:59:00
Posted by: SlightyDazed

This CPU guide is great but it doesn't cover the following proposed Pentium upgrade, and as such I wonder is this upgrade is a first for socket 479ers.

I am running a Pentium Dothan 'M' 780 at 2266Mhz on a FSB of 533Mhz in a Socket 479mPGA with an ATI chipset, and want to upgrade the cpu to a Mobile Pentium '4' HT 552 at 3460MHz -a SL7NC. The Mobile Pentium '4' HT's VID and bus speed are both fully supported by the existing hardware. However HT is not supported on this machine either in the BIOS or by the motherboard, but both cpus operate on the same 90nm architecture. Here I am guessing that Pentium '4' would run but run without the HT element.

Without the HT code implementation there will be a process loss but does anyone know if such an upgrade as this is still possible or even worthwhile?

PS : I have seen elsewhere Intel suggest on the same topic to another curious upgrade newbee that as the chipset on this Toshiba(GENERIC NO ID)MoBo is non Intel(the chipset is ATI RS400/RC400/RC410 with a SB400 Southbridge) then without a manufacturer's bios update such a proposed crossover in socket 479 Pentium cpus will not be supported by the chipset drivers.

Response: Socket 479M does not support Pentium 4.

Upgrade of Socket 479mPGA from Pentium 'M' to Pentium '4'

2010-09-04 17:40:48
Posted by: SlightlyDazed

Thank you for the response CPU World.

Sandra reveals my socket and board combo specifications as supporting a FSB of 400 or 533 or 800MHz. Currently the board is running an Intel Dothan 2.26GHz with a bus of 533MHz, this bus speed was I believe one of the Intel 'Centrino' characteristics. The original processor, as supplied by Toshiba was a Celeron M Processor 360 @1.40 GHz, with a 400 MHz FSB. The upgrade path I have followed thus far fits the socket 479 projected upgrade path exactly as CPU World have determined it should for this type of cpu.

Sandra also reveals the chipset is, as I first suspected it was - a non Intel one, an ATI RS400/133 Host Bridge which is capable of supporting all of the following bus frequencies, 400, 533 and 800MHz(all quad pumped).

The exact and full Sandra description for the type of socket 479 in my Toshiba Satellite L20 laptop is "FC(muy)PGA 479M".

Toshiba on their advice forums have advised the owner of a identical chipset and socket combos to upgrade their cpu from one with a 533MHz bus to a cpu with a bus speed of 800MHz. This Toshiba suggest would fully exploit the board's full speed in DDR2 memory.

With this unspecified bus speed in mind I would be grateful to 'CPU World' if they could throw some light upon the following statements that appear by way of expanation and definition for socket 479:

"Socket 479, also called mPGA479M".
The nomenclature used is not identical to the Sandra description of the socket and neither are the specifications or descriptions when compared to Wikis entry for the socket M which by extension, according to CPU World, is ostensibly the same socket:

Wiki on Socket M states that:
"Socket M (mPGA478MT), also known as Socket 479 mPGA"
This statement defines Socket M as a 479 socket. Wiki reports that Socket 'M' supports bus speeds of 533 MT/s, 667 MT/s, and 800MT/s which tallies but again only in part with my socket specifications.

CPU World's socket specification on the other hand for the 'socket 479, also called mPGA479M' itemises as follows,'The socket 479 works with mobile processors with frequencies up to 233 MHz and FSB frequencies up to 667 MHz'. Again this tallies but only in part with my socket 'FC(muy)PGA 479M'specifications and note here there is no mention of the mysterious 800MHz bus.

As neither socket name or description appears to proffer an exact offering or match in terms of description or specification this leads me to suspect that here there might well be a socket 479 which thus far has defied accurate specification or description, certainly the bus speeds seem at the very least to suggest this as a possibility.

I note that professionally there really is an element of doubt and reservation as to wether my proposed 'M' to 'P4' upgrade would or would not work.

Without there being sufficient or adequate information on the Toshiba socket in terms of definition, specification or an adequate working knowledge of the electrical compatability of pin modes it seems only natural, to an amateur such as me, that I should remain intrigued, more than a little confused, and possibly even a tad sceptical concerning the received wisdom and opinions as to the likelyhood or not of such an upgrade IE from Pentium M to Pentium P4 being successfull.

There is just one final possibility as to the origin and purpose of the 800MHz bus, and it might have nothing at all to do with defining or redefining a new 479 socket at all. The 800MHz bus speed's inception and incorporation might have been implemented because there were at that time some Via cpus which could handle a bus speed of up to 800MHz. The generic/annon board manufacturer in offering a board which could accomodate all three of the world's leading cpu manufacturers chips was perhaps doing nothing more complex or intriguing than making a decison founded upon nothing more than good business sense.

Response: Pentium M pinout:
Pentium 4 pinout:
Please compare them side by side, and you will see that Pentium 4 cannot be used in Pentium M socket.

the claim that the pentium 4 doesn't work with socket 479

2012-06-29 05:11:06
Posted by: Talon_one

i'm sitting here looking at the processor socket in a machine that i've been using for two years and it's a socket 479 and guess what it had in it, a pentium 4, you need to do a little more research before telling people stuff guys, just a word of advice

Response: I'd be happy to correct it, but I need more information before doing that. Please post pictures of the processor and the socket.

look this

2012-10-03 07:01:39
Posted by: Hellus

On the Web seen a post with photos of someone who has done it, search for "Laptop Socket 479 upgrade"

Response: Sorry, I can't find it. There is a thread titled "Laptop Socket 479 upgrade", that talks about upgrading Celeron M to Pentium M, but it doesn't say anything about using Pentium 4 in socket 479. Or, did I misunderstood you comment?

socket mpga479m, celeron 2ghz to p4 2.66ghz

2013-07-11 15:33:59
Posted by: Steelman

I'm no expert by far just like to tinker with computers but, I have an old Fujitsu w/ p4 2.66GHz 533mhz bus speed and a Toshiba satellite a15-s127 with socket mpga479m/foxconn holding a mobile Celeron 2ghz 400mhz bus I switched them out of curiousity and it worked fine only problem I saw would be the terrible CPU fan in the toshiba. So keeping it cool might be an issue. Hope this helps

Upgrade of Socket 479mPGA from Pentium 'M' to Pentium '4'

2014-02-27 19:41:39
Posted by: Andrei Cristea

The Pentium M you own is faster and more efficent than the Pentium 4 you wish to replace it with.


2014-05-21 08:23:26
Posted by: a thankful man

Thanks very much for your great website!

Intel ARK is maybe more beautiful but you deliver much more
information about sockets and processors, please continue providing this informations :)

Last modified: 10 Mar 2014
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