The problems with Vista 32bit and 4GB of RAM are well documented but does anyone out there actual know of a motherboard that will display and use the 4GB properly please.

Better that they know from experience please, or it may be that a type of chipset and SP1 will fix it.

I currently run an E6600 and 2x 1GB of DDR2 6400, added another 2x 1GB of exactly the same RAM and blue screens everwhere.

So if I could utilise the memory and E6600 that would be useful but if I have to buy another board and core duo then so be it.

Thanks

Vista 32 and SP1 will display 4GB RAM on any MB. You must use a 64 bit OS to allocated 4GB or more system RAM. Depending on your system hardware, video card, etc., your Vista 32 OS will use 3.0-3.2 GB of system RAM.

http://support.microsoft.com/kb/929605/en-us

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.

its not the mb falt mate

If the problems started after you added the other 2GB of RAM, it sounds like that RAM is faulty.

I agree with runswindows95. You may have defective RAM. At least you would have to properly volt and set up timings and speed in BIOS. Running memtest on each DIMM individually would weed out the bad DIMM(s).

Thanks for the defective ram tip but either pair work fine on their own. I tried the new pair for a week on their own for a week and they were ok. Before this I also ran extensive memory tests using PC Check V6, again no problems run as a mixture of 2x 1GB but very quick failures when used as 4 x1GB.

I was just hoping someone out there could say, Yep, I am using 'this' motherboard, with 4GBs of ram; it may only show 3.5GB but it is certainly faster than 2GB - I would rush out and gratefully buy one!!

Thanks again.

Relax ram timings to JDEC standards, and increase ram voltage bit by bit until it runs stable.

Ya your OS will only be able to address 4gb total no matter what mobo, e.g.
3500mb RAM + 500mb vid card = 4000mb total. Even if you have 4gb installed, its just your video card.

Are you overclocked? bobknights suggestion sounds appropriate. Have you got the lastest Bios for your mobo, what mobo is it? are you forcing a speed setting on your new ram and not letting them run at the speed of the slowest?

Thanks Guys
No not overclocked at all. Just standard or optimised settings if they had them.
MB: Gigabyte GA-965P-DS4 (rev. 2.0)
Bios v10 (latest not beta, beta ones say for CPU ID and 45mm)
Core Duo E6600
Corsair DDR2 1GB 6400 800mhz 5-5-5-12 x 4

Just seen a new chipset driver on the motherboard dirver list so will run that - is that update relevant please?

Like Badge and doomturkey have stated its a 32bit limitation even if the mobo shows you have 4 gigs installed it changes nothing. Windows 32bit can only address a max of 4 gigs can only alocate a max of 2 gigs per program. you can get whatever mobo you want it will change nothing. you will only be able to alocate from 3 gigs to 3.7 gigs to windows use as the video cards memory has to be mapped to the OS think of it as caching it is in effect using that ram its not showing for your video card. The only way to avoid this limitation is move to a 64bit OS. Only those two people gave you advice that was at all usefull everyone else i have no idea wtf they are talking about.

just for refference its not a problem with vista 32bit or a motherboard it is a inherant limitation in 32bit operating code. The well documented problem isnt even a problem. You guys really got to get over this being a bug or saying windows cant use 4 gigs since it is more then capable of using a total of 4 gigs just remember where all 4 of those gigs are coming from.

BTW there was a bug with installing vista with exactly 4 gigs of ram not sure if that happens on 32bit but install vista on 2 gigs and install whatever patch it was to fix the 4 gig problem. I thought it was only ultimate 64 that had that problem however.

Do you know? The only reason 32bit Vista cannot go beyond 4GB is because Microsoft has programmed that limitation into it.

Have you memtested both sets independently?

does it immediately start blusecreening? or only have a period of time? could it be temp related, i.e. as the north/south (north I think) gets warm the extra load put on it by 4Gb causes it to get a bit warm, or behave badly if it already is warm. Open case and blast it with air to see if it is better.

You could reduce the speed of the memory to 5400?, i.e. 533Mhz, so that it runs at 1:1 with the CPU, the performance drop will be very small, this would dramatically reduce load on certain key components and should mean that the memory itself is less stressed.

What I'm thinking is that many overclocks stop working when you go from 2 to 4Gb, as the extra stress from 4gb is too much in an overclocked state. So if (for various reasons) your mobo is close to the edge but in a state of standard clocking then the extra RAM could hurt. Reducing this load may help.

However all mobo's (except those that specifically state it, typically with only 2 slots) should cope with 4Gb or even 8Gb. But as others have pointed out the limit on a 32bit OS is not mobo related and is just one of those facts of life.

Hester7:

2^32 = 4,294,967,296bits, = 4Gb so unless microsoft invented binary notation purely to have a 32bit OS stop at 4Gb you're not helping. (of course Bill will at some point claim this no doubt.)

Also, read the post, the OP is concerned about bluescreens more than the loss of 0.5Gb.

I wasn't addressing the OP in that post. And the fact is, the physical address space can easily be extended beyond 2^32 in a x86 OS

Something similar to the LBA patch for HDD's?

memory access is probably a very low level part of windows and would have been developed at the time when 64Mb was a lot. So its time to move to 64bit OS's, the fact that they don't work properly yet and have driver bugs and limited compatibility is more MS's fault.