DV9000T & 4G RAM revisited

[troispuits]

Hi,

I read this forum and saw a lot of confirmation that the HP DV9000t laptop does indeed support 4G of RAM. I went out and bought 2 modules of 2G RAM today, but my Vista Ultimate 64 bit only sees 3G in System Properties even though both BIOS and CPU-Z report all 4G. I have the latest BIOS V F.28 installed. I know that my RAM modules work, because I swapped out each module and test them along with the original HP RAM modules.

Could anyone please help?

Thank you in advance,

[Airman]

You need a 64-Bit operating system to use all 4GB of RAM. There are endless threads about this already....

[SmoothTofu]

He stated that he was using vista ultimate 64 bit.

[troispuits]

I am running Vista Ultimate 64 bit....

[v3loc1ty2.0]

so you should be able to use 4GB with no problem at all...
try reseating the ram

[vhmike73]

I know on my dv9000T, Vista Ultimate x64 did not show all 4 GB of RAM that I had installed. Not sure why the 64-bit OS it wouldn't read it when the BIOS DID reflect the full amount installed. (I'm at f.27 now, but was at f.26 when I had the 64-bit install on the machine)

So, for confirmation purposes, I can concur he's seeing an anomoly. As for a good reason why the x64 version of Vista won't read 4 GB on this laptop (mine is a dv9000T with the 945GM chipset, 2.0 GHz Core 2 Duo, GeForce 7600 discrete graphics), I'm also at a loss. Intel's specs on that particular chipset specify that it will support up to 4 GB at 533 and 667 MHz speeds, so it may be something HP is doing...I guess. Doesn't matter- due to conflicts with some software I needed to use, I regressed to x86 Ultimate, so I'm not going to see all 4 GB anyway right now!

Maybe I'll slap in the x64 drive and see what I get with the latest BIOS (it's up to f.28 now)...

[chrixx]

All 945 chipset laptops will not see the full 4GB, despite using a 64-bit OS. Only dv9500t, based off the 965 chipset can address 4GB (this isn't confirmed on the Pavillion models, but it does on other notebook models).

[Airman]

Ahh my bad, as far as I know only the Santa Rosa models will fully support 4GB on a 64 Bit system. I believe Chrixx to be correct.

[Seth Oriath]

So, only the AMD versions of the dv9000 can see 4gb when on a 64-bit OS?

Well, that sucks.

I guess I can forego the idea of bumping my system to a 4gb/Vista64 system then and just go for swapping out one of my mem sticks for a 2gb chip.

I thought I'd read somewhere that the 945 chipset supported up to 4gb of memory...oh well.

EDIT: Wait a minute...according to Intel's tech specs on the 945GM Express chipset ('ftp://download.intel.com/design/mobile/datashts/30921905.pdf') (what's used in the dv9000t series, at least according to HP from what I can tell), it supports up to 4gb of memory.

1.1 Mobile Intel® 945GM/GME Express Chipset
Feature Support
1.1.1 Processor Support
• Intel® Core™2 Duo mobile processor, Intel® Core™2 Duo mobile processor LV
(Low Voltage), Intel® Core™2 Duo mobile processor ULV (Ultra Low Voltage)
• Intel® Core™ Duo processor, Intel® Core™ Duo processor LV (Low Voltage),
Intel® Core™ Duo processor ULV (Ultra Low Voltage)
• Intel® Core™ Solo processor ULV
• Intel® Celeron® M processor (Intel Core processor based), Celeron M processor
ULV
• 533-MHz and 667-MHz front side bus (FSB) support
• Source synchronous double-pumped (2x) Address
• Source synchronous quad-pumped (4x) Data
• Other key features are:
— Support for DBI (Data Bus Inversion)
— Support for MSI (Message Signaled Interrupt)
— 32-bit interface to address up to 4 GB of memory
— A 12-deep In-Order Queue to pipeline FSB commands
• AGTL+ bus driver with integrated AGTL termination resistors
1.1.2 System Memory Support
• Supports single-/dual-channel DDR2 SDRAM
• Maximum Memory supported: up to 4 GB at 400, 533 and 667 MHz
• 64-bit wide per channel
• Three Memory Channel Configurations supported:
— Single-Channel
— Dual-Channel Symmetric
— Dual-Channel Asymmetric
• One SO-DIMM connector per channel
• 256-Mb, 512-Mb and 1-Gb memory technologies supported
• Support for x8 and x16 devices
• Support for DDR2 On-Die Termination (ODT)
• Enhanced Addressing support (XOR and Swap)
• Intel® Rapid Memory Power Management (Intel® RMPM)
• Dynamic row power-down
• No support for Fast Chip Select mode
• Support for 2N timings only
• Supports Partial Writes to memory using Data Mask signals (DM)

EDIT 2: Well, here's a Microsoft Knowledgebase article ('http://support.microsoft.com/kb/929605/en-us') that I found:

SYMPTOMS
If a computer has 4 gigabytes (GB) of random-access memory (RAM) installed, the system memory that is reported in the System Information dialog box in Windows Vista is less than you expect. For example, the System Information dialog box may report 3,120 megabytes (MB) of system memory on a computer that has 4 GB of memory installed (4,096 MB).

Note You can access the System Information dialog box in the following ways:• Click Start, type System in the Search box, and then click System under Programs.
• Double-click System in Control Panel.
• Click Start, right-click Computer, and then click Properties.
• Click Show more details in the Windows Vista Welcome Center window.

Back to the top

CAUSE
This behavior is the expected result of certain hardware and software factors.

Various devices in a typical computer require memory-mapped access. This is known as memory-mapped I/O (MMIO). For the MMIO space to be available to 32-bit operating systems, the MMIO space must reside within the first 4 GB of address space.

For example, if you have a video card that has 256 MB of onboard memory, that memory must be mapped within the first 4 GB of address space. If 4 GB of system memory is already installed, part of that address space must be reserved by the graphics memory mapping. Graphics memory mapping overwrites a part of the system memory. These conditions reduce the total amount of system memory that is available to the operating system.

The reduction in available system memory depends on the devices that are installed in the computer. However, to avoid potential driver compatibility issues, the 32-bit versions of Windows Vista limit the total available memory to 3.12 GB. See the "More information" section for information about potential driver compatibility issues.

If a computer has many installed devices, the available memory may be reduced to 3 GB or less. However, the maximum memory available in 32-bit versions of Windows Vista is typically 3.12 GB.
Back to the top

WORKAROUND
For Windows Vista to use all 4 GB of memory on a computer that has 4 GB of memory installed, the computer must meet the following requirements: • The chipset must support at least 8 GB of address space. Chipsets that have this capability include the following:• Intel 975X
• Intel P965
• Intel 955X on Socket 775
• Chipsets that support AMD processors that use socket F, socket 940, socket 939, or socket AM2. These chipsets include any AMD socket and CPU combination in which the memory controller resides in the CPU.

• The CPU must support the x64 instruction set. The AMD64 CPU and the Intel EM64T CPU support this instruction set.
• The BIOS must support the memory remapping feature. The memory remapping feature allows for the segment of system memory that was previously overwritten by the Peripheral Component Interconnect (PCI) configuration space to be remapped above the 4 GB address line. This feature must be enabled in the BIOS configuration utility on the computer. View your computer product documentation for instructions that explain how to enable this feature. Many consumer-oriented computers may not support the memory remapping feature. No standard terminology is used in documentation or in BIOS configuration utilities for this feature. Therefore, you may have to read the descriptions of the various BIOS configuration settings that are available to determine whether any of the settings enable the memory remapping feature.
• An x64 (64-bit) version of Windows Vista must be used.
Contact the computer vendor to determine whether your computer meets these requirements.

Note When the physical RAM that is installed on a computer equals the address space that is supported by the chipset, the total system memory that is available to the operating system is always less than the physical RAM that is installed. For example, consider a computer that has an Intel 975X chipset that supports 8 GB of address space. If you install 8 GB of RAM, the system memory that is available to the operating system will be reduced by the PCI configuration requirements. In this scenario, PCI configuration requirements reduce the memory that is available to the operating system by an amount that is between approximately 200 MB and approximately 1 GB. The reduction depends on the configuration.

...

I *think* I understand what that article is saying (the closer you get to maxing out RAM, the more RAM is set aside outside of Vista's usage for devices). But if someone wants to clarify me, that'd be great :-D

[troispuits]

Just a little note to let you know that after installing Vista SP1 RC, my Vista Ultimate 64-bit is able recognize all 4G on my laptop (DV9000t)....

[Greg]

Just a little note to let you know that after installing Vista SP1 RC, my Vista Ultimate 64-bit is able recognize all 4G on my laptop (DV9000t)....

If you read the release notes, you'll find that this is because Vista will now report the amount of memory physically installed. It does NOT mean you have 4GB available...in fact, your amount of available memory does not change.

Regarding the OP's question/problem, 4GB of RAM needs two things:
1) 64bit OS
2) A 965 chipset or later

You have #1, you do not have #2. This is because, despite Intel releasing 64bit processors, their chipsets were not designed for anything but 32bit memory addressing until the 965 chipset was released (which is also when 4GB+ of RAM actually became financially feasible for most consumers). Even with a 64bit OS you are still only going to be able to use as much as a 32bit OS could.

[Envision]

Thanks for the great post Greg!

[Greg]

I'm just sorry it isn't the answer everyone was hoping for :(

[Envision]

That's the upside and the downside of technology, the truth is either greatest news or the worse news. No matter what though, it is always best to be 100% sure of something in technology, and that means learning through experience or learning from others.

[orev]

It's also the downside of an immoral marketing department and an industry that does little to question anyone's claims.

"Intel releases 64bit CPUs!!" too bad the chipset doesn't support any of the main advantages of them.

"Intel releases Santa Rosa with 800MHz FSB!!" Too bad the only thing that can talk at 800MHz is the CPU itself. RAM isn't on the FSB, and only runs at 667MHz.

I'm glad I returned my dv9000 when I did.