Computer not recognising my shiny new RAM.

[spookymuffin]

Until today I had 3GB (three 1GB sticks) of RAM in my computer. I wanted to buy some more (since I upgraded to Vista) so I picked up a 2GB stick to fill my remaining slot.

So I should have 5GB of RAM now.... but I'm not sure if I do.

DxDiag now says that I only have 2GB installed (it seems that I've managed to lose RAM in the process) , as does any other option I can think to check while I'm in my operating system. The thing is, my bios says that I have 5GB of RAM installed and working.

Which is correct?

Any help is much appreciated.

[jsalemi]

Hmm, most current computers require two sticks of the same type to make up memory, so I'm surprised your computer even saw the 3GB in there (it should have only seen 2GB). Try getting another 2GB stick and replacing one of the 1GBs with it and see if that makes a difference.  This is of course assuming you use DDR2 RAM -- if not, then this may not apply.

And if you have XP, having more than 2GB is kinda useless, since XP only really uses up to 2GB of RAM.  Vista uses more, I believe, but since I don't Vista (and won't for the foreseeable future), I don't know how much it can use.

[spookymuffin]

Yeah, it's DDR2.

When I had XP installed it certainly acknowledged the existence of my 3GB even if it wasn't using it. Vista seems to think that I only have two of five installed for some reason.

I suppose I'll have to go out and buy another 2GB stick to pair with it 

[Jelenedra]

Errr. Really? Because I was told they didn't have to be the same size. I had a GIG and half for awhile.

Are all of your RAM sticks made by the same manufacturer? Some sticks don't like talking to each other. So it could be that when you stuck the new one in, it decided it hated RAM stick A so now the two of them are too busy fighting with each other to be accessible.

[spookymuffin]

Are all of your RAM sticks made by the same manufacturer? Some sticks don't like talking to each other. So it could be that when you stuck the new one in, it decided it hated RAM stick A so now the two of them are too busy fighting with each other to be accessible.

I have a big hodge-podge of brands. I have the two sticks that came with my computer and then a stick that I bought later (different brand) they all worked together. I bought this 2GB stick today different brand from my original pair and the third stick.

[Jelenedra]

That could be it. When I upgraded to 2 gigs, my shiney new Kingston hated my PNY. So, I went and got two kingston.

The way to check for this though, would be to remove all the sticks but the new one. If your PC can read the new one, that means that it is a compatability issue with the other RAM. If it can't... you got a busted stick. Return it.

[spookymuffin]

Thanks. I'll give that a shot when I get home.

[Argon]

Until today I had 3GB (three 1GB sticks) of RAM in my computer. I wanted to buy some more (since I upgraded to Vista) so I picked up a 2GB stick to fill my remaining slot.

I'm assuming you installed the 64-bit version of Windows Vista yes? If you're still using a 32-bit OS (like Windows XP or anything below Vista Ultimate unless you request the 64-bit disc from Microsoft) the higher memory simply cannot be addressed (each section in memory needs an address, for example 0x00A64CFF - made it up just for illustration; once you run out of spaces ie. 0xFFFFFFFF the pc can't see anything past that.)

[spookymuffin]

@Argon, I'm running the 32-bit version. 64-bit doesn't support sli apparently and I have dual video cards.

After doing some more research I found a few possible ways to work around my problem.

 I enabled PAE, following the intructions here: http://vistarewired.com/2007/03/29/how-to-enable-more-than-35-gb-of-memory-in-32-bit-windows-vista/. It didn't change anything.

I downloaded Vista service pack 1 and installed it. This did actually make a difference. My system menu now says that I have 5GB installed. However, dxdiag still says that I only have 2GB installed.

I'm not really sure how trustworthy dxdiag is since it displays the incorrect amount of memory for my dual video cards aswell.

My system is certainly running faster; but as to whether that's from the newly recognised RAM or the service pack I don't know.

[Zazazu]

Until today I had 3GB (three 1GB sticks) of RAM in my computer. I wanted to buy some more (since I upgraded to Vista) so I picked up a 2GB stick to fill my remaining slot.

I'm assuming you installed the 64-bit version of Windows Vista yes? If you're still using a 32-bit OS (like Windows XP or anything below Vista Ultimate unless you request the 64-bit disc from Microsoft) the higher memory simply cannot be addressed (each section in memory needs an address, for example 0x00A64CFF - made it up just for illustration; once you run out of spaces ie. 0xFFFFFFFF the pc can't see anything past that.)

Huh? I'm running Windows XP and 4 gigs RAM. It definitely recognizes it and, since I upgraded from 2 gigs to 4, things like flipping between programs like Photoshop and SimCity4 and Sims2 are almost instantaneous. It's a definite improvement. I see the correct amount of RAM listed in dxdiag and under Help and Support Center...Computer Information:
Processor Intel(R) Pentium(R) D CPU 3.00GHz
Processor Speed 2.92 GHz
Memory (RAM) 4096 MB
Operating System Microsoft Windows XP Home Edition
Operating System Version 5.1.2600

[KatEnigma]

32 bit versions of Windows won't USE more than 3.something GB of RAM, but it will see it.

[Argon]

Not in the system properties window it won't. Search the KB articles on Micro$oft's website, the HAL (Hardware Abstraction Layer) can't see it so nothing else in the OS will know it's there. It is a limitation of a 32-bit data path, you see it in other operating systems as well.

[J. M. Pescado]

32-bit machines cannot show more than 4 GBs of all memories. If you have more than that, nothing happens. Even that alleged Vista hack will not enable Vista to actually see that many RAMs.

[KatEnigma]

But shouldn't it be showing him/her 3 GB, or 4 GB, not 2?

[bowrain]

Maybe it only recognizes the new 2 GB stick and ignores the three 1 GB sticks?

[spookymuffin]

Well my OS can certainly see all of my RAM.



Are you saying that even though it shows up as 5GB above that it is still not using all of it?

[J. M. Pescado]

Probably it sees 2 GB, then, because Vista is chewing up the remaining 3. You *ARE* using VISTA, after all.

[spookymuffin]

Probably it sees 2 GB, then, because Vista is chewing up the remaining 3.

But when I had only 3GB installed that all showed up fine.

You *ARE* using VISTA, after all.

I would have prefered to stay with XP but I got a pair of 8800 GTS cards for my birthday and I didn't want their directX 10 capabilities to go to waste.

[KatEnigma]

Well my OS can certainly see all of my RAM.



Are you saying that even though it shows up as 5GB above that it is still not using all of it?

Yes, that's exactly what we're saying. 32 bit systems can only use a little over 3 GB of RAM. That's it. Now if you had in 4 GB, it wouldn't be that much overkill, since your drives need to use some RAM too, and they can use the extra. But 5? Complete waste.

[Zazazu]

Ah, good. I didn't want that 4th stick to feel unwanted. Wasn't that expensive (I think I paid $40 a stick). Theoretically, when I upgrade my HD, it'll use more RAMmage.

[Hegelian]

You might want to read this:  Vista Workshop: More RAM, More Speed.

Most users will be sobered when they equip their systems with 4 GB of RAM and find that only 3 GB is recognized by the BIOS and by Windows. This is neither a bug nor due to any hardware error. The explanation is simple: 32-bit systems can only address up to 4 GB of memory. Additionally, many add-in cards and on-board controllers require memory addresses in order to be accessible. This is called "Memory Mapped IO" (MMIO). Since this memory range has to lie within the 4 GB, it is subtracted from the installed and available RAM.

Thanks to a technique called memory remapping, it is possible to move around parts of the system memory in such a way that the full 4 GB is still available for use. The trouble is that this feature had to be deactivated in Windows Vista due to compatibility issues.

In order to be able to utilize the entire system memory, you will therefore need to use a 64-bit version of Windows Vista. In this article, we will take a look at memory usage under the 32-bit and 64-bit versions of Windows Vista, and analyze how the operating system behaves with different amounts of RAM.