2 Replies Latest reply on Oct 16, 2015 3:27 PM by Ascaris

    82PM965 Express Chipset Memory Capacity...


      Hello fine people,

      This will help me potentially upgrade my laptop. It started with trying to determine if Win7 64bit would run on it in spite of Dell's assertion that it could not. All indications were that the Intel components seem acceptable to this end so I started looking into it and have run into these questions regarding RAM support. I need an Engineer interested in shooting holes in my plan. You can stop reading now if you can't help with clarification about the specifications for the Intel PM965 chipset and/or skip to the bottom for the root questions.

      I'm seeking technical documentation and advice on the maximum memory supported by an Intel 82PM965 controller. I am aware that Dell is the primary source of information regarding this, but they are simply not knowledgeable and seem to lack access to documentation. The box is a Dell Inspiron model 1720 laptop with a T8300 processor and PM965 chipset. The BIOS is Dell's A09 (the most current and last ever update). It is of course legacy equipment but a perfectly good piece of hardware that I've had since new. I used the Chipset Identification Utility to positively identify the chipset here:




      Detected Chipset:

      Intel(R) PM965 Express Chipset

      Chipset Components

      Memory Controller:


      I/O Controller:

      Intel(R) 82801HBM/HEM I/O controller hub (ICH8M) SATA Controller found in AHCI mode

      Integrated Graphics:

      Gfx String not set


      The Intel ARK page for this device provides the following information concerning memory:



      Mobile Intel® PM965 Express Chipset
      (Intel® 82PM965 Memory Controller)



      -Memory Specifications
      Max Memory Size (dependent on memory type) 4 GB                                   <<======= This is some of the information I seek clarification about.
      Memory Types DDR2-533 / DDR2-667          <<======= What does "dependent on memory type" above really mean? (specifically)
      # of Memory Channels 2
      Physical Address Extensions 36-bit
      ECC Memory Supported  No






      It is widely "known" (or accepted) that the max RAM is 4GB on this Inspiron. That is the only documentation available and what Dell clings to as well. Others have done real world "experimentation" seemingly proving the 4GB limit to be wrong. There seems to be no issue with stability etc. In a nutshell:

      1) 6 GB RAM seems proven to work.

      2) 8 GB RAM seems proven NOT to work (the machine will lock at POST, likely a BIOS limitation )

      3) The mismatched 2GB/4GB RAM combo seems proven to still allow dual channel operation. (Intel® Flex Memory Access might explain this.)

      Please see these URL's to clarify what I'm saying above. They may at least be informative to the desired outcome.

      Inspiron 1720 with 6GB RAM Tested

      Continuation of Dell Inspiron 1720 mods.... - PC Hardware Discussion/Reviews | DSLReports Forums


      Now, aside from all the self indulgent back-patting going on at these links, they appear to contain enough relatively solid technical info to be noteworthy. I'm simply attempting to mitigate my risk of throwing good money away on RAM that may be doomed because of a lack of documentation and clarification about the 965 chipset.

      Memory Configuration Tools at various memory vendors say that DDR2 speeds of PC5300 (667 MHz) OR PC6400 (800 MHz) SODIMMS will work. It should be noted that the URL's above both seem to use PC5300 DDR2. The DDR2-533 in the specs above would indicate PC4200. Perhaps this is enough background so now on to the root questions:

      1) Will the PM965 support more than the 4GB referenced in the specs above and if so, under what conditions? (i.e. With DDR2 PC5300 only etc.)

      2) What does "Dependent on Memory Type" in these short specs really mean? (what are the details, variables, requirements etc?)

      3) Can it be confirmed that it supports DDR2 PC-6400 RAM with an 800 MHz FSB? (The PM965 specs above don't indicate that, but the T8300 processor in the system seems to indicate that it must).

      4) What other considerations concerning the PM965's role might I not be properly considering? (i.e. MUST the CAS latency of the RAM be the same? Other "tolerance" or limitation considerations? I'm aware of normal "best practices" when using dual channel RAM configurations.)

      5) If 6GB of RAM seems feasible, what might be done to keep everything happy and not inadvertently cripple performance in spite of more RAM? (i.e. proper chipset drivers to use, RAM latency or type considerations etc.)

      Thank you all in advance,


        • 1. Re: 82PM965 Express Chipset Memory Capacity...

          Hi Mike,


          I completely understand what you are trying to find so let me help you with that.


          First of all, I would like to thank you for posting this here since I am sure there may be other users with this doubt.

          The following information is the memory support for Chipset PM965:




          This information can be found at this link on page 12:



          Please note that the information there is standard data and what I mean to say is that the chipset itself supports that; however, we as Intel provide the hardware to Computer Manufacture and they will design their own units setting certain limitations or allowing the system some permissions but this again, depends on the Computer Manufacture.


          As an example of this, we developed a board with similar specifications or chipset series. The motherboard model is DP965LT. If you take a look on the board Technical Product Specification you will find that we have tested different memory configurations for this motherboard. Check page 18 of the following link:



          So I can confirm that 4GB of RAM can be used with that chipset but when talking about 6GB and different speeds that depends on the limitations that have been or not by the Computer Manufacture.


          Now, Checking on the laptop manuals, I found that the computer can handle up to 4GB with DDR2 667MHz  as memory type but I found a very informative forum that may help you:



          Hope You find it helpful.


          Kevin M

          • 2. Re: 82PM965 Express Chipset Memory Capacity...



            I know that more than a year has passed since you asked your question, so you probably have found an answer by now... but it is still marked as unanswered.  At  the very least, maybe I can help the next person who finds this thread through a search for the same info.


            I don't have the model of laptop you do, but I do have an Asus F8Sp-X1 with the PM965 chipset.  I can confirm that it does work with 8gb; it is running right now, with all 8gb recognized in the BIOS and in Windows.  It also works just fine with Windows 7 x64 (and did so even before I upgraded to 8gb), which is what I am using.  It would appear that the PM965 chipset, despite what Intel says, can handle 8gb without issue, even if they only "support" 4gb.


            As for the failure of the Dell with 8gb to POST: Did the people who tried it use SoDIMMS with 16 chips each (8 per side)?  The reason I ask is that I saw a comment on the Asus forum from someone who had also upgraded a F8S* to 8gb, and he had said it will only work if you use the double-sided modules with 8 chips per side (16 total per module).  If that was what the people you read about were using, then it is probable that your assessment about the BIOS is right.


            The modules I have are DDR2-800, and even though CPU-Z does report that the SPD correctly identifies the modules as PC2-6400 (DDR2-800), they are only running at DDR2-667 speed.  The CPU in use is the T7800 (Core 2 Duo 2.6ghz, 800mhz FSB). 


            The PM965 chipset can use dual channel mode with two differently sized modules (which, in my AMI bios, is called "dual channel L shaped mode").  If you put in a 2gb and a 4gb module, the first 4gb will be dual channel; the last 2gb will be accessed in single channel mode.  While this is a configuration that most of us would not prefer to use, it is somewhat common for laptop makers to configure their devices this way.  My F8Sp came with 1x1gb and 1x2gb, for example.


            When I was researching all this stuff myself in preparation for my memory upgrade, I remember reading an article about how MSI was showing a new laptop to one of the various tech bloggers out there, and he was surprised to see the two memory slots were populated with different-sized modules.  MSI told him that in their tests, the single-channel vs. dual-channel difference was trivial.  Later on, he tried some tests himself, and confirmed what he'd heard.  It's not even close to the "running at half the speed" point that many people on various forums often will say about single-channel mode. 


            At the very least, 6gb in L shaped mode is almost certainly going to be better than 4gb in full dual channel mode.