The fact that the bios recognizes the RAM means nothing to Windows. Vista
works the RAM much more intensely than any previous version of Windows ever
did. If you don't have "precisely" ***matched*** RAM - you may well have
problems.
I previously had 2-500 meg sticks of matched RAM. I wanted to move to 2 gig
of RAM. I purchased 2 NEW 1 gig sticks of RAM (at the same time to be
certain they even came from the same date/batch/lot). I could have just
purchased a single 1 gig stick and I would have had 2 gig. The RAM would NOT
have been matched - even though it was all identified in the bios.
--
Regards,
Richard Urban
Microsoft MVP Windows Shell/User
(For email, remove the obvious from my address)
"Andrew McNab" <AndrewMcNab@discussions.microsoft.com> wrote in message
news:AB2FB012-2807-46C5-B9B3-5D61141976D0@microsoft.com...
> In my original post, I made it clear that the BIOS properly recognised the
> memory. All 4 SIMS are 667MHz and both memory channels have matched SIMS.
> The
> conditions can't be any more ideal.
>
> The mother board supports 800/667 etc with up to 8GB addressed at 64-bits.
> I
> also stated that i'm using 3 SIMS for now. The original pair and a single
> sim
> in the second memory channel making it 3GB. I've tested both SIMS and
> they're
> fine.
>
> The obvious question is, why is there a discrepency between the BIOS and
> Windows in terms of the amount of memory that is installed in the machine?
> BIOS reporting 4072 and Windows reporting 3582 with all four SIMS and both
> reporting 3000 with 3 SIMS.
>
> Having been a developer on every version of Windows since Windows for
> Workgroups 3.11, i'm more inclined to believe it's a teething problem.
>
> "Richard Urban" wrote:
>
>> If your system is crashing when you install the extra RAM you must look
>> at
>> the manual for your M/B to determine what the RAM specifics are. All 1
>> gig
>> sticks RAM are not the same. Some are single sided. Some are double
>> sided.
>> There are timing frequencies. The list goes on.
>>
>> --
>>
>>
>> Regards,
>>
>> Richard Urban
>> Microsoft MVP Windows Shell/User
>> (For email, remove the obvious from my address)
>>
>>
>>
>> "Andrew McNab" <AndrewMcNab@discussions.microsoft.com> wrote in message
>> news:C28EC6C8-EAE6-4087-8C8D-F8354E669D18@microsoft.com...
>> > I've been running Vista Ultimate on 2GB of RAM fine but decided to
>> > upgrade
>> > to
>> > 4GB because the prefetch cache got up to 1.4GB. My BIOS reports 4075MB
>> > of
>> > installed and useable RAM. Supports up to 8GB.
>> >
>> > Windows Vista only reports 3528MB RAM and results in a Blue Screen
>> > crash
>> > when logging in or shortly afterwards. I tested the 2 new SIMS by
>> > themselves
>> > and tried combinations of the original 2 SIMS and either of the 2 new
>> > SIMS
>> > to
>> > make 3GB. Windows reports 3GB of RAM and runs fine.
>> >
>> > I was wondering if there was an issue with a certain amount of memory
>> > the
>> > OS
>> > can work with at this point. I'm running Vista Ultimate with the latest
>> > OS
>> > updates.
>>
>>