up vote 17 down vote favorite
3
share [g+] share [fb]

If I want to add more RAM to my computer, how can I buy something compatible? What kinds are there? How do I determine which kind my computer will accept and how much I can add?

link|improve this question
62% accept rate
Possible Duplicate: superuser.com/questions/9826/ram-capacaty-of-my-computer – Diago Aug 6 '09 at 12:19
3  
@Diago, not a duplicate, that question would not be easy to understand for someone just wanting to know how to upgrade RAM. – Ash Aug 6 '09 at 12:24
feedback

8 Answers

up vote 15 down vote accepted

Although CPU-Z focuses on processors, it also provides detailed info about the RAM for the current computer.

Run it and note down the details in the "Memory" and "SPD" tabs and use that to determine what sort of RAM your system supports.

Note it is Windows only.

alt text

The CPU-Z "SPD" (Serial Presence Detect) tab shows you what RAM is currently installed in your computer. Most (all) motherboards support one DDR version only DDR DDR2 DDR3 etc, so you know you will need to buy RAM of the same DDR version.

Each Slot in the dropdown corresponds to a physical slot on the MB (may be empty).

You can normally install various sized RAM modules such as 256MB, 512MB 1024MB, 2048MB in each slot.

However total maximum RAM supported varies by Motherboard. Also, a 32Bit OS such as Windows XP will only be able to utilise up to 4GB of RAM, regardless of how much you install.

link|improve this answer
2  
512MB is the current size. Only your motherboard manual cal tell you the max RAM size. – John Gietzen Aug 6 '09 at 12:30
@Nathan, yes CPU-Z shows you what is currently installed in your computer. Most (all) motherboards support one DDR version only DDR DDR2 DDR3 etc, so you know you will need to buy RAM of the same DDR version. Each Slot in the dropdown corresponds to a physical slot on the MB (may be empty). – Ash Aug 6 '09 at 12:33
You can normally install various size RAM such as 256MB, 512MB 1024MB, 2048MB in each slot. However total maximum RAM supported varies by Motherboard. Also, a 32Bit OS such as Windows XP will only be able to utilise up to 4GB of RAM, regardless of how much you install. – Ash Aug 6 '09 at 12:37
If you tell us what your motherboard model number and manufacturer are, we can probably tell you the max ram you can take. Do you know how much you have, and in how many sticks? – RJFalconer Aug 6 '09 at 12:43
Use the same application and check the mainboard tab. – Nifle Aug 6 '09 at 12:49
show 3 more comments
feedback
up vote 19 down vote

Crucial is a good place to buy RAM and they have a System Scanner (Windows/Mac only) to analyse the memory that is present and recommend upgrades.

link|improve this answer
There is now a Mac scanner (in beta). Their site seems to detect your OS and points you to the right one. – Pauk Aug 6 '09 at 15:00
Thanks I was checking from Linux and it only showed the Windows version. I have updated my answer. – Mark Aug 6 '09 at 15:40
feedback
up vote 3 down vote

CPU-Z is definitely a good bet. I also use SIW which is a bit more general and gives info about your whole system too:

SIW is an advanced System Information for Windows tool that gathers detailed information about your system properties and settings and displays it in an extremely comprehensible manner.

link|improve this answer
feedback
up vote 1 down vote

If you just have the model number of the computer - especially useful when you're upgrading a friend's computer and you can't run a utility to work it out - Kingston's website has a great "Search by Manufacturer" tool that will tell you the exact bank layout of most recent computers and all the constraints (e.g. whether you have to pair the memory). You can then get standard RAM from anywhere that matches the specs; you don't need to get the expensive Kingston system-specific RAM.

Most modern PCs are pretty straightforward physically to put RAM into, except for some netbooks.

link|improve this answer
feedback
up vote 1 down vote

It should also be noted that Windows XP cannot* address more than 4GB of memory, so no matter how much you put in beyond that you can only use 4GB worth.

*Sometimes the following command seems to get past the limit;

BCDEdit /set PAE forceenable

This command will only work on XP and Vista, and is apparently disabled on Windows 7.

link|improve this answer
What is that command doing? – Nathan Long Aug 6 '09 at 12:44
1  
That command enabled Physical Address Extensions, which can be used to address more than 4GB of ram in a 32bit environment in certain situations. The processor and motherboard must both support it, iirc – Keck Aug 6 '09 at 12:49
feedback
up vote 0 down vote

Many motherboard manuals can be found online, and the RAM specs should be contained within.

link|improve this answer
Then there is the question "How can I tell which motherboard I have in my computer ?" – Gnoupi Aug 6 '09 at 15:44
Go ahead and ask it! Seems like a valid question for this forum. – Mark Ransom Aug 6 '09 at 16:19
CPU-Z mentioned above will give you the name of your motherboard if you look at the mainboard tab. – Pär Björklund Aug 6 '09 at 16:34
feedback
up vote 0 down vote

Go to kingston.com or apacer.com, they have huge database of computers manufactured and give you compatible module types and sizes for your computer.

link|improve this answer
feedback
up vote 0 down vote

Open the case, take out the ram sticks and identify them visually. This might help you get an idea what specs the RAM is (PC3-800 or something like that). It is not the most reliable method, though.

link|improve this answer
Be aware that this doesn't guarantee the RAM will work flawlessly or at the speed it's rated at. – slhck Jan 29 at 16:35
feedback

Your Answer

 
or
required, but never shown
discard

Not the answer you're looking for? Browse other questions tagged or ask your own question.