64 bit operating systems and 4 GB's of ram

[Ferrit]

So I am running Vista Ultimate 64
Now that ram is so dam cheap i have 4X1 gig sticks of ddr2
Issue here is that Vista 64 does not see the 4 gigs
The operating system itself sees 3 gigs.
Now the bios also only sees 3 gigs
MSI K9A Platinum motherboard
Now here is the fun part.
When using Mirc in chat and doing a sysinfo it shows 4 gigs
Ok aint that a daisy. Several other odd programs show 4 gigs as well
How in the name of all thats reasonable can bios not see it yet a software program inside of windows can?
I am nearly sure I am not suffering from too many loose screws.
I mean if you have a harddrive connected incorrectly and bios doesn't see it,
I cannot imagine some software inside windows will see it

Sysinfo from mirc shows this
<Ferrit> (RAM) Used: 2.27GB Free: 1.73GB Total: 4GB Used percent: 56%
Hehehehe
Any one with any info jump right in.
Oh and I did an update to the bios to see if that would help and killed my board in the effort. Ups died at a most inopportune time. Which was inconvenient but not totally fatal. I just got another board and carried on searching this 64 bit 4 gig memory limitation thing.
Its now officially become an "ISSUE" with me.
It was my understanding that 64 bit had no such limitation.

[houseisland]

Hi Ferrit,

My understanding is that the memory issues w. the XP/Vista 64-bit OSs are hardware/driver related and not with XP/Vista themselves -- I have been known to be wrong, though.

Theoretically you should be able to install 128 Gb of RAM.

Whether the hardware platform supports this and how drivers/hardware deal with memory addressing are different matters.

From Wikipedia re XP:

"Windows XP x64 is currently limited to 128 GB of physical memory and 16 TB of virtual memory. Microsoft claims this limit will be increased as hardware capabilities improve. In practice, most motherboards compatible with 64-bit processors do not support anywhere close to the maximum limit, and often retain the 4 GB limit, though motherboards capable of 8GB are becoming more common."

http://en.wikipedia.org/wiki/Windows...al_x64_Edition

I haven't seen any similar problems with 64-bit Windows 2003 servers (using same basic OS kernel as XP x64, I think) running on tier-one-type hardware (IBM & HP), but then the hardware and drivers are developed to support the 64-bit OS and the reason for going to the 64-bit OS is generally the need for massive amounts of memory.

I suspect that such support is lagging behind on desktops, particularly desktops with bleeding-edge-gamer hardware where R&D bucks are probably focused still on hardware/drivers for the 32-bit OS evironment.

Maybe....

[CCT]

The AnandTech review of that board is clear in that it supports the full 4 Gb.

However, http://support.microsoft.com/kb/929605 .

[Ferrit]

This board is supposed to be capable of 8 gigs that is true.
I see nothing in the bios which might be considered memory remapping.
Will email MSI tech support

[houseisland]

Hi,

I have a socket AM2 board which will accept 8 Gb of RAM. At present I have 4 Gb of RAM installed. The BIOS sees the 4 Gb. Linux sees the 4 Gb. MemTest86 sees the 4 Gb. XP i86 (32 Bit) theoretically supports 4 Gb of RAM but this is only 4 Gb of memory address space. XP sees only 3.5 Gb of memory. This is because the various hardware I have installed is mapping memory addresses within the 4 Gb memory space and thus XP cannot use those memory addresses for RAM. If I pull my 256 Mb eVGA video card and install an 8 Mb Mach64 PCI card, XP sees more of the 4 Gb of memory.

So my point here is that the problem may be in how your adapter cards and their 64 bit drivers map their memory addresses. If they still map within the 4 Gb memory space rather than above (say if the drivers were badly ported over from 32 bit to 64 bit versions) then it could explain the problem you are seeing.

Maybe.

[Ferrit]

tks houseisland another avenue to investigate.
HIS X1950 PRO so cats and I should imagine those drivers are ok but who knows

[houseisland]

The Inquirer: 6GB OCZ memory works on Vista 64 bit, 27 December 2006

It is possible.

[slgrieb]

Never to be overlooked is the possibility that one module might have some minor defect such as a timing issue that prevents the MOBO from detecting and using it correctly. No matter what other tests report. You know the drill from here; remove and reboot, etc.

[Ferrit]

Issue has been resolved. A newer bios off the MSI forums has cured the issue totally. It is stable but one side note .
This board sets the voltage for the ram at 1.9 which it appears is too low.
2.0/2.1 seems more favorable and is not outside specs so I have it at 2.1.
Nice not to have ram lying around doing nothing after paying for it even if its cheap.
Thanks to all who replied.