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I'm considering upgrading my system memory from 1 GB (2 x 512MB) to 4 GB (1 x 2 GB + 1 x 1 GB + 2 x 512MB). I'm an absolute novice at this stuff but am trying to learn quickly. The RAM is DDR2 and I want to buy with a proper match. My system is a Dell Vostro 200 Desktop.

Details are:

Northbridge Intel P35/G33/G31 rev. A2
Southbridge Intel 82801IR(ICH9R)rev. 02
Memory Type       DDR2
Memory Size       1024 MBytes
Channels          Dual, (Symmetric)
Memory Frequency  332.5 MHz (3:5)

Please guide me. I have 32 bit system. 4 ram slots. do not want to lose previous 2 DIMMs of 512 MB too. Also, Is my selection of memory proper or is there a particular way to choose RAMs?

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What model of dell computer is this? That would be the best way to tell what type of RAM to purchase (assuming the RAM you have installed is the original). Look up the model of the dell (say if it was an optiplex 360) then I would google Optiplex 360 RAM to find out what the max amount of RAM the system can support. Keep in mind if you mix and match RAM with two different speeds, the computer will default to the slower of the two speeds so dont waste your money on faster RAM if you plan on keeping the old RAM installed. – Richie086 Dec 3 '13 at 23:01
@Richie086 It is Dell Vostro 200 Desktop PC with original configuration with which it was shipped – kattybilly Dec 3 '13 at 23:07
As DDR2 is fairly old now, you can buy any matched set of DIMMS and pop them in. Why only 4GB of ram though ? and why do you want to keep the 512MB sticks ? – Lawrence Dec 4 '13 at 0:59
@Lawrence - Anything more then 4GB is a waste of money since the user is using a 32-bit operating systems. I won't argue the semantics of my statement so don't bring up PAE because there are several "except ..." when you enable PAE within Windows. – Ramhound Dec 4 '13 at 13:03
@Ramhound I never assumed that the OP was using Windows, but it's probably a safe assumption, so I'll accept that. I'm still wondering why keep the 512MB sticks and not just go for 2x2gb sticks though... – Lawrence Dec 4 '13 at 14:01
up vote 1 down vote accepted

On a 32 bit system you probably do not gain more usable memory than 3GiB.
Keeping your old 2 x 512MB means that you do not need to add more than 2 GiB.

You can do this either as 1x 2GiB or as 2x 1GiB. The last may be roughly 3% faster.

If you think you later change the OS to a 64 bit version then it is worth it to get more memory. E.g. get 2x2GiB or 2x4GiB. This is assuming you have a 64 bit CPU, but googling shows that most Dell Vostro 200 combination have a core2duo and [](those are 64 bit CPU's).

So nothing is stopping you from using a 64 bit OS. (barring if you till use XP, but XP should be dumped in the next few months since there will be no more updates for from after the 8th of april 2014.

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That's not quite true anymore, with modern Operating Systems, Physical Address Extension (PAE) will enable a 32-bit OS to be able to use up to 64GB of memory – Lawrence Dec 4 '13 at 0:56
True. PEA can be used for that. But not all drivers play well with it and if you have 64 bit capable hardware you might as well use a real 64 bit OS rather than a 32+4 bit OS (And still with 2/4GiB per program limitations). – Hennes Dec 4 '13 at 1:30
@Lawrence - While PAE will allow a 32-bit operating system to use an application to address more then 3GB of memory, the desktop versions of Windows have very specific limitations, and its safe to assume based on the technical ability of the user and the fact its OEM hardware they are not using Linux. While it also is possible to hack desktop versions of Windows to get around their specific limitations, its unfair to the author, and unwise as techical experts to suggest such a hack to the user. – Ramhound Dec 4 '13 at 13:01

To expand on Zach L's answer, we don't know you exact motherboard model (posting the model of your Dell computer would help), but based on the information provided, it's safe to say that you currently have a motherboard that supports DDR2 RAM modules (the individual sticks of RAM are called "DIMMs") and you are currently using PC2-5300 modules, based on your memory frequency.

Here's what you need to know to upgrade your RAM:

  1. You must buy DDR2 RAM

Your motherboard may not accept any other kind of RAM. Here's an explanation of why, for instance, first-gen DDR RAM won't work (from Wikipedia):

DDR2 DIMMs are not backward compatible with DDR DIMMs. The notch on DDR2 DIMMs is in a different position from DDR DIMMs, and the pin density is higher than DDR DIMMs in desktops. DDR2 is a 240-pin module, DDR is a 184-pin module. Notebooks have 200-pin modules for DDR and DDR2, however the notch on DDR2 modules is in a slightly different position than on DDR modules.

  1. You must buy paired/matching DIMMs that run at the same speed and install them in paired sockets, or buy a single DIMM and

Zach L and others have explained this already. You must also install your identical/paired RAM DIMMs in paired slots (if there are four slots, it will be apparent which ones are paired by how close they are to each other). It doesn't matter if you install your DIMMs in 1&2 or 3&4 on most motherboards, but for simplicity you can install them in 1&2.

Edit: As Hemmes points out below, there may be a scenario in which you buy a single DIMM of DDR2 RAM. In that case, you must install it in DIMM slot #1.

  1. You may want to get faster memory than you currently have installed, but only as fast as your system can use.

The memory bus on your computer can only utilize the full speed of memory up to PC2-6400. Buying faster RAM then that will not have any effect on system performance due to the limitations of your computer's Front Side Bus. I'd recommend you buy PC2-5300 DDR2 RAM (the kind you already have) or PC2-6400 DDR2 RAM (the fastest kind that your machine can use).

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I disagree with "You must buy paired/matching DIMMs that run at the same speed and install them in paired sockets.". A single DIMM (e.g. 1x 4GiB) would work just fine. – Hennes Dec 4 '13 at 0:29
@Hennes -- I wasn't aware that they made 4GB DDR2 DIMMS in PC2-5300 or PC2-6400. It's possible they're out there, but I have never found any. I'll update my post with directions for installing a single DIMM. – Stephen Lynch Dec 4 '13 at 0:33
They seem to exists, albeit not cheap enough to seriously consider them. – Hennes Dec 4 '13 at 0:41

RAM is chosen based on what is compatible with your chipset & motherboard. I looked up your Northbridge & came across an Intel Offical PDF. On page 8 of the linked PDF, I found a quick breakdown of what data transer rates were supported for DDR2 RAM. I selected the higher data rate (PC2-6400) to, hopefully, find higher quality products. I popped over to & searched for PC2-6400 DDR2 RAM. Here's a couple of examples of acceptable products: 2GB (1GBx2), 4GB (2GBx2). Those should set you on the right track.

I feel it should noted that your chipset supports dual-channel memory, which increases overall efficiency by a small margin. If you're doing anything that pushes how much memory you're using, I would suggest using matched sets. (Heck, I suggest using matched sets no matter what. It avoids possible memory conflicts, however rare they may be.)

Lastly, Richie086 is correct about the speed issue. The machine will default to the lowest speed of the available RAM.

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You can use the Crucial Advisor Tool.

It will give you all details about what you want once you fill your motherboard type model.

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