Installing more RAM on my PC

  renard 22:41 10 Feb 2011

As I am increasingly getting Windows “low virtual memory” warnings, I have been advised to install more memory on my PC – a Dell Dimension C521.

A system scan by reveals that I have 1GB of RAM installed and three empty slots. They recommend installing up to three extra 1GB in matched pairs and offer to sell me “guaranteed compatible” RAM for £14.39 per GB.

Presumably adding 3GB will be beneficial? However, Crucial’s advice includes two things I don’t understand.

1. It says “Your PC can handle 4096 MB”. I get confused over MB and GB. Can I have a total of 4GB RAM on my PC?

2. In saying each memory slot can take 1GB, it says “Not to exceed manufacturer supported memory”. I don’t understand that.

Also, you will probably have realised that my knowledge is limited, albeit I am fairly intelligent (!). Is it easy for someone inexperienced to install extra RAM?

Any advice will be greatly appreciated.

  Forum Editor 23:23 10 Feb 2011


“Not to exceed manufacturer supported memory”. I don’t understand that."

It means that you can't just install any old RAM.

Do exactly what the Crucial scanner has recommended - it can be trusted.

"Is it easy for someone inexperienced to install extra RAM?"

Yes, it is.

1. Open the case.

2. fit the new RAM modules into the slots provided, and ensure that the retaining clips click into place.

The RAM modules can only be inserted one way, and you'll easily see which way that is by studying the modules and slots - there is a notch on the module that correspinds to a lug on the slot.

Replace the case, and turn the computer on - the BIOS will detect the new RAM as it does its Power On Self Test (POST), which is the bit that happens in white text on a black background before Windows loads.

You should find that upgrading the RAM makes a big difference.

  lotvic 23:47 10 Feb 2011

1Gb = 1024Mb
2Gb = 2048Mb
3Gb = 3072Mb
4Gb = 4096Mb

Maximum memory for your pc is 4 GB (4096Mb)
Have a look at the Specifications in the Service Manual it tells you all about what you've got.

Your manuals homepage click here
service manual click here
click on: Removing and installing parts >click on : Memory
and you get full instructions with pictures.


“low virtual memory” = page file (amount of harddrive space that the OS (XP) can 'pretend' is RAM and use it as extra)
This should be set to 1and a half times the actual RAM. You have 1GB so it should be set at 1 and half Gb (1536Mb)
If you add more ram then increase the page file to match.
rightclick on: My Computer > Properties > Advanced tab > Settings button > Advanced tab > and look at Virtual memory and click on Change if it is not the right size for the amount of ram you have got.
If you look at the bottom it will tell you how much is 'Recommended' so you can't really get it wrong :)
You could just put green dot in 'System managed size' if you wanted or you can enter it yourself if you choose 'Custom size'

Any problems post back on here and we'll try to help :)

  iscanut 10:20 11 Feb 2011

If you are using Win XP then your system will only use about 3.5Gb. What OS do you have ? It is VERY easy to install your own Ram modules.

  Terry Brown 14:13 11 Feb 2011

Just a word of caution.

When working on ANY internal or your computer make sure the power plug is Unplugged and you are using an Anti-static strap on your wrist.

click here

These are quite cheap and will prevent accidental damage to your computer from static that may be stored in your body or carpets etc.


  renard 16:49 11 Feb 2011

" iscanut
Fri, 11/02/[email protected]:20
If you are using Win XP then your system will only use about 3.5Gb. What OS do you have ? "

I have XP. If RAM should ideally be in matched pairs, presumably my options are either 2GB or 4GB total. Therefore, if XP uses 3.5, it is best to install total 4GB - yes?

  Ian in Northampton 20:00 11 Feb 2011

Personally, I'd say that unless you're a very heavy duty user, 4GB is overkill for XP. In most cases, it runs fine on 512MB, very well on 1GB and fairly hums along on 2GB. After that, I think the difference you'll notice would be marginal. On the other hand, at £14 a stick from Crucial - who cares? :-)

And yes, as FE said, upgrading RAM is one of the more straightforward things you can do in the case. No jumpers to set, no cables to connect, not even any screws to undo/do - it just plugs/clips in, and it won't go in the wrong way round.

  iscanut 20:48 11 Feb 2011

2Gb would be fine but if you can afford 4gb, go for it as Ian says !

  renard 21:16 11 Feb 2011

Thanks for all this great advice, which is very reassuring.

Just one more worry: Having now studied my PC User Manual, I find the following advice about installing additional memory -

"If possible, do not pair an original memory module with a new memory module. Otherwise, your computer may not start properly."

Well, I hope to install an extra 3GB to get a total of 4GB as seems to be the consensus on this post. Obviously I intend to pair a new module with the existing one, rather than buying four new ones. Should I follow the above advice, or is it OK to pair the new with the old?

  lotvic 00:14 12 Feb 2011

You have not said what speed the existing stick is so remember that if you install mixed pairs of DDR2 533-MHz (PC2-4300) and DDR2 667-MHz (PC2-5400) memory, the modules function at the slower installed speed.

If you want to install 4 x 1Gb sticks then if it was me I would buy 4 new 1Gb sticks if the existing one is at the slower speed.

(Although my Dell is currently running on 3Gb total. I have 2 of 512Mb sticks and 2 of 1Gb,
originally it came with 2 of 512Mb sticks and I added the extra 2Gb last year)

  rickf 10:50 12 Feb 2011

IF your M/B is capable of 2g per slot I would go for 2x2gbs into 2 slots. They come as matched pairs and much cheaper. Crucial is very good but tenbds to be more expensive. If you know the specs of your Ram buy from say eBuyer or Novatech.

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