Vista 64bit running SP1 build 668 RRS feed

  • Question



    I have just upgraded my Lenovo T60P with 2 x 2 GB memory.. The bios shows 4gb, and the same does the system information in Vista 64 bit.


    But the Task Manager only shows 3069 of total physical memory, what to believe.


    Is this a bug in vista or some hardware limitations. The T60P does support 4gb, according to the spec.





    Tuesday, January 22, 2008 2:47 PM

All replies

  • I didn't see this problem in my spec.

    You might interested on try to reinstall Vista 64 without SP1 first then try again.

    Wednesday, January 23, 2008 1:07 AM
  • The 4 GB figure is the installed memory.  The lower figure is after memory space has been reserved for PCI slots, video and other hardware all of which take up memory space.  If your motherboard can only handle 4 GB, then the hardware must use space in the 4 GB range to operate.  If your motherboard can handle more than 4 GB, then the hardware memory space can be set outside the first 4 GB.  In any case, when you install RAM up to your motherboard's limit (4 GB, 8 GB or whatever), some will be reserved for hardware.


    Tom Lake


    Wednesday, January 23, 2008 1:45 PM
  • Hi,


    That might be correct, but I have 2 scenarios.


    1. Vista running 64bit SP1 build 668, with 2gb memory. It shows, 2gb in bios, 2gb in System Properties and 2gb in Task Manager.


    2. Vista running 64bit SP1 build 667, with 4gb memory, It shows, 4gb in bios, 4gb in System Properties and only 3gb in Task Manager.


    Would the issue that You (Tom Lake) describe only exist with 4 gb and not 2. The memory space reserved for PCI slots, video and other hardware, would still exist is running in scenario 1 is that not correct ??.. So in scenario 1, the Taskmanager would then only show 1gb of memory instead of 2. 


    Or am I wrong about that.




    Thursday, January 24, 2008 8:58 AM
  • The problem only shows up when you're using the maximum RAM your motherboard can hold.


    Here's a quick diagram.


    |---------------------------------------------- 4 GB Motherboard Maximum --------------------------------------------|


    Your computer with 2 GB RAM:

    |-------------------------2 GB RAM-------------------------|----Unused Space-----|-----------Hardware------------|


    Your computer with 4 GB RAM:

    |-----------------------------------------3.25 GB RAM------------------------------------|===RAM &Hardware===|


    When you have less than 3.25 GB or so, your RAM is all seen.  When you have more

    than approx. 3.25 GB, RAM and hardware space overlap and overlapped RAM is deactivated.

    Actually, the overlapped RAM may be pushed above the 4 GB mark but it's still unavailable to

    your motherboard which has a 4 GB ceiling.


    Tom Lake

    Thursday, January 24, 2008 9:53 AM
  • Hi Tom...


    Is this a chipset limitation for the Intel 945. I have heard of others with no problem.





    Friday, January 25, 2008 9:00 AM
  • Hello :

    I am a part of the Windows Vista SP1 Development team at Microsoft. We’re sorry you are not having a good experience with Windows Vista SP1. We would like make you aware that Windows Vista customers are entitled to no-fee support for issues that relate to the SP1 update from Microsoft Help & Support.  Microsoft Help & Support provides you with email, chat, or telephone support where you can talk to a Microsoft Support Agent to assist in troubleshooting your installation issue.  Please click on this link and open up a case with our product support services teams: . Thank you for taking the time and we look forward to hearing from you.  

    Saturday, March 22, 2008 3:36 PM