While the world has been focused on the launch of Intel's desktop Core 2 Duo, codenamed Conroe, Intel has been readying its mobile counterpart also called Core 2 Duo.  With only a few changes to its desktop counterpart -- mainly its lower clock speeds and FSB frequency and thus lower power -- there's no reason to call the mobile version anything but Core 2 Duo. 

There hasn't been much interest in Core 2 Duo on the mobile side for two major reasons; for starters, unlike on the desktop, Intel already had a very competent mobile CPU - the Yonah based Core Duo processor.  Seeing as how Core Duo is the predecessor to Core 2 Duo, you can already expect that Intel's current mobile performance is quite good. 

The other major reason there's not much hype surrounding Core 2 Duo in notebooks is because there's simply not the level of competition from AMD that we had on the desktop.  While AMD's Turion 64 and Turion 64 X2 are good processors, you simply can't find them in nearly enough notebooks, and definitely not in as unique packages as you can find Intel's Core Solo and Core Duo processors.  AMD is hoping to rectify this situation by both working on a lower power mobile CPU architecture and acquiring ATI to help complete its platform offering on the mobile side. 

Without tough competition from AMD, and with an already excellent platform, there's simply no reason to get excited about Core 2 Duo on the mobile side; we're quite content as is.  But with mobile Core 2 Duo processors priced identically to Core Duo processors, there's no reason to complain.  Intel isn't asking for any more money, leaving us with two questions: how much more performance are we getting, and what happens to battery life?  

It's those two questions that we'll be answering here today, hopefully giving recent purchasers of Core Duo notebooks a reason to kick themselves or breathe a sigh of relief. 

New Processor, Old Centrino

Before we get to talking about Core 2 Duo in notebooks, it's worth mentioning that Intel's Centrino marketing won't change with the introduction of the new processors.  Although Centrino has taken a virtual backseat to Core 2 in recent months, the rules still remain unchanged.  In order for an OEM to be able to call its notebook a Centrino or Centrino Duo it needs to meet the following requirements:

  CPU Chipset Networking


Intel Core Solo or Pentium M

Mobile Intel 945 GM/PM/GMS

Intel PRO/Wireless 3945ABG

Centrino Duo

Intel Core Duo or Core 2 Duo

Mobile Intel 945 GM/PM/GMS

Intel PRO/Wireless 3945ABG


Being able to sell a notebook as a Centrino or Centrino Duo is particularly important as Intel has invested a lot of money into the brand; in theory, the Centrino label should help sell your notebook better than without it.  From Intel's perspective, the Centrino platform ensures that each OEM has to buy three pieces of Intel silicon instead of just one.  Now you can see why AMD wants to get into the chipset market with ATI. 

The important takeaway point from the above table is that Centrino Duo notebooks can use either Core Duo or Core 2 Duo processors. There's no additional branding designation if your Centrino Duo notebook comes with a Core 2 processor. 

Backwards Compatibility

Intel's Core 2 Duo mobile launch is one of those very rare moments in Intel history where a brand new CPU is introduced and it is backwards compatible with existing motherboards. 

If you've got a Core Duo notebook with a PGA Socket-M interface, all you should need is a BIOS update and a Core 2 Duo CPU to upgrade your notebook.  If you've got a BGA CPU, then you're unfortunately out of luck as desoldering 479 balls from your motherboard without damaging it isn't for the faint of heart. 

Obviously there are some caveats, and you'll want to check with your notebook manufacturer to make sure it supports Core 2 Duo on your particular model before upgrading.  As far as Intel is concerned, the only stipulations for Core 2 Duo support are on the chipset side and are as follows:

 CPU 945GM 945GMS 945PM 940GML

Core 2 Duo


Not Supported


Not Supported

Low Voltage Core 2 Duo




Not Supported

Ultra Low Voltage Core 2 Duo




Not Supported


If you've got a 945GM or 945PM equipped notebook, then the Core 2 Duo should be a drop in replacement for your Core Duo processor.  The upcoming Low Voltage and Ultra Low Voltage Core 2 Duo processors will also work in the 945GMS chipset, and none of them will work in the 940GML chipset. 

Model Numbers Galore
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  • saleemi - Saturday, February 28, 2009 - link

    what is the difference between Dual Core and Core 2 Duo processor?
    I want to buy a laptop what i will do?
    Can some body please explain the difference..
  • kem - Thursday, December 6, 2007 - link

    I have a notebook with a 940GML / Celeron 440. Can i upgrade to a CoreDuo FSB533?
  • tatpeng - Sunday, December 2, 2007 - link


    I would like seek your advice. I want to buy laptop but i confused on the Centrino Duo Core 2 Duo and Intel Core 2 Duo. I looking at the Acer Aspire Laptop Centrino Duo Core 2 Duo and Compaq Presario Intel Core 2 Duo. So i would like to know the difference. Please assist. Both is Core2 Duo but the Acer is with Centrino. Is Acer better or Compaq better?
  • a rabbit - Wednesday, August 30, 2006 - link


    A few questions:

    (1) Can we assume that the power draw numbers represent the best possible performance one can expect from Core 2 Duo mobile systems one can purchase today, or, should we assume that they represent typical performance, or, can we say we don't know because we only used one sample of Core 2 Duo?

    (2) What about the Core Duo (Yonah)? Theoretically, if Intel supplied all CPUs to the reviewer, I as Intel would supply the best quality (lowest power draw) Core 2 Duo, and the worst quality (highest power draw) Core Duo for my reviewer to perform the review on.


    -a rabbit
  • chetech - Friday, August 11, 2006 - link

    Can a Core 2 Duo processor be fitted into an Apple Mac Mini using their new Intel Core Duo processors?
  • wimh - Thursday, August 10, 2006 - link


    one of the funny things about performance and battery life is that if you can complete a task quickly enough thus returning your CPU to an idle state faster, battery life will grow even though instantaneous power consumption may be higher.

    Actually this is not correct: a CPU that's clocked higher also needs a higer voltage. Therefore, doing the same amount of work faster will require more energy than spreading it out over a longer time (in theory).
    For this to be true in practice, you'll off course need to factor other things into account, like I/O-devices (which may have less choice in sleep states: keeping the hard disk spinning for a longer time can destroy the gain you had by slowing down the CPU), etc...
  • devilzangel - Tuesday, August 8, 2006 - link

    "Eventually" we will have processors based on light particles vs electrons; but that is "eventually"; lets talk about the very near mobile future shall we (1 year).

    1. EM64T enabling - Will DEFINATELY boost and widen the performance gap b/w Core D & Core2 D. Especially with the Vista 64bit OS system installed. EVEN when u run 32bit applications on it.

    2. Quad-Core 'Santa Rosa' - Another great stride by Intel to boost performance (of course at the expense of battery life (which i might add, shouldnt matter much since most laptop users use the laptop near AC outlets). I am definately going to wait until next year to upgrade to a new laptop. Plus Vista will take advantage of the extra cores.

    3. FSB, and Battery Life - Comon, lets not fool ourselves; Intel can full well come out with a 1066 config for mobiles WHENEVER they want. AND mobile MOBO can be fabricated to take advantage of it JUST as fast. BATTERY life is the ONLY culprit. I would be the FIRST to buy such a laptop. Why use a clumsy desktop with so much wattage when you can get slightly less performance with much better gains to offset the balance regardless. Lets get one thing straight ... Desktops are losing ground, Laptops are the future.

    4. Shared L2 Memory Cache - The 1st Core D processors were CRUDE at best in this regard. Core 2 D Proc.s will SHARE the FULL L2 cache.

    Ehh who knows what will happen in 2008, and 2009 .. IBM and Georgia Tech's 300GHZ (room temperature) processors may be producable by that time ..

    Sometimes, I feel as if the corporate giants stagger the new technology into consumer hands in stages so that they may reap the profits.

  • ViperV990 - Tuesday, August 8, 2006 - link

    Regarding the FSB vs battery life issue, can't they just throttle the FSB dynamically like they do with the multiplier? I mean, come on, I've been able to change the FSB speed on the fly using software since like what, the Celeron 300A days?

    (Forgive me if that was possible earlier. My earliest overclocking experience was with a Klamath P II 266...)
  • devilzangel - Tuesday, August 8, 2006 - link

    In the older processors and mobos it may have been easier to access this code settings to allow HIGHER speeds than mentioned limits ..

    normal throttling of CPU, Cache, FSB, Fanspeed etc, is part of the architecture (or so i understand it to be) .. 'Over'throttling the FSB is something i am unsure of .. at best it is a risk.

    recently though, most (if not almost all) boards have such options blocked or hidden in Bios settings and chip configurations (except the higher end GA, Asus, DFI, Abit boards).. ofcourse it very possible (and it wouldnt surprise me if it is) that the Core 2 D are ALREADY capable of 1066FSB but the chips have been locked onto 667, or 800 (the architecture of the C2D desktop chips is pretty much identical to the meroms, almost); it is possible that such mobile settings may be unstable if someone managed to crack the coding and change the frequency settings. The causes could range from MOBO coding chips, to Heat issues

    It is kind of like apple; we the consumers found out around the beginning of this year that Apple always had a somewhat working version of their OS for intel hardware settings.

    remember the technology staggering .. the FSB is part of it. It is like Diamonds, and Oil; limit the supply of higher and faster technology to increase the chances of a higher profit history overall.

  • IsLNdbOi - Monday, August 7, 2006 - link

    I've got a Toshiba U205-S5002 which has a 945GM chipset. This article says that the 945GM supports Core 2 Duo. I need to find out now if the processor in my laptop has a PGA Socket-M or BGA CPU. I've checked Toshiba's support pages, but can't find any info. regarding the CPU's interface w/ the mobo.

    Anyone have any info. regarding the U205-S5002's CPU interface?

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