RAM (a.k.a. "Memory")

• Acronym: Random Access Memory
• Synonyms: "System memory", "memory"
• Measured in: Megabytes (MB)
• Common denominations: 32MB, 64MB*, 128MB**, 256MB, 512MB***, 1024MB

*Minimum requirement for Windows 2000
**Minimum requirement for Windows XP
***Minimum requirement for Windows Vista

NOTE: RAM is frequently referred to as simply "memory".

How do I check how much RAM my computer has?

PC (Windows XP)

Macintosh (OS X)

Do I have enough RAM?

Probably not, since most manufacturers like to skimp on how much RAM they put in their machines. Here's the list of minimum RAM requirements for Windows:

Windows Minimum RAM Requirements

Windows 98/ME	Windows 2000	Windows XP	Windows Vista
32MB	64MB	128MB	512MB

However, these numbers represent the absolute BARE minimum. While it is possible to run these operating system with this amount of RAM, you will be accessing your virtual memory all the time, causing severe slowdowns. Here's a list of more realistic numbers:

Realistic Windows RAM Requirements

-	Windows 98/ME	Windows 2000	Windows XP	Windows Vista
Minimum	32 MB	64 MB	128 MB	512 MB
Lean	64 MB	128 MB	256 MB	1 GB
Normal	128 MB	256 MB	512 MB	1.5 GB or greater

Yes, you read right, that's a suggested 512 MB for Windows XP (both Home and Professional). Just XP by itself on normal settings scarfs down about 212 MB of RAM, which leaves most "standard" configurations with only 46 MB left for other programs.

"Lean" is what most computers manufacturer's like to pass of as "normal," which is technically true--Windows will run normally on "lean" amounts of RAM if nothing else is running in the background. Check your system tray: if you see more than 6 icons, you aren't running a "lean" machine, so to speak, and probably need a "normal" amount of RAM.

What do I do if I don't have enough RAM?

You have two options:

1. Buy more RAM (see below)
2. Try to trim your machine down to "lean" status. Instructions on doing this can be found here.

How can I get more RAM?

Please see our guide to buying more RAM.

I think my RAM is bad. What should I do?

Contact the student helpdesk at x18062 and arrange to bring in your computer (if it's a laptop) or make a Room Service appointment (if you have a desktop). If you have a PC, we can use the MemTest utility to diagnose failing memory chips.

If MemTest detects bad memory, you can try swapping it with a compatible chip, if you have one. Otherwise, a good place to look for new memory is http://www.crucial.com . This site will help you find the best price on memory compatible with your computer.

What if I have a Mac?

Macs are notoriously picky about the kind of RAM they will work well with. If your system is acting very flakey or you're seeing lots of Kernel Panics, bad memory is a likely culprit. Crucial offers the same RAM that Apple does on their site, but at a much cheaper price.

What is "virtual memory"? (a.k.a the "paging file" or "swap file")

Sometimes your computer needs to use more RAM than it actually has. In order to make up the difference, it uses some space on your hard drives and "pretends" that it's just like normal system memory (RAM). This "virtual" memory is also known as your computer's paging file.

Unfortunately, your hard drives transfer data at a MUCH slower rate (on the order of 100 times slower), the practical offshoot of which is that your programs will run verrrry sloooowwwllllyy. As it turns out, Windows always uses a little virtual memory for its own mysterious purposes, but if it must resort to using VM every time you open a new program, you're experiencing a RAM shortage.

So, how can you tell when your computer is tranferring stuff into virtual memory? Check your hard drive activity light: if it starts flashing (usually accompanied by the "clicking" noise that computers make when accessing hard drives) every time you start up a program (or even boot into Windows), you're probably overusing your virtual memory. There are two causes for this:

1. You have too many programs/services/spyware instances running at the same time (see Computer Cleanout)
2. Your computer doesn't have enough RAM (see the RAM buying guide)

Frequently, the cause is a combination of these two. Users running Windows XP with 256MB or less will probably experience RAM shortage. First try cleaning out your machine -- if things are still running slowly, consider buying more RAM.

How do I change how much virtual memory my computer uses?

Well, the answer is that Windows will use as much or as little as it really feels like. However, you can set maximum and minimum values for the file, as well as change its location.

Go to Start > Control Panel > System > Advanced Tab > Settings button in the Performance box > Advanced> Tab > =Change button under Virtual Memory

From there you can change max, min, and location values.

What does RAM actually do?

• Your computer uses RAM to store information that it needs to remember in the short-term. Any program that you are running (as well as your operating system) uses RAM to do whatever it is it needs to do. The more programs you want to run, the more RAM you have to have. If your computer is running slowly, or takes forever to boot up, or your hard drive activity light is constantly flashing, you may be experiencing RAM shortage. For more information on RAM-shortages can be found here.

What is RAM? (not really vital to know, read if you're interested)

• On a basic level, RAM is very much like a person's short-term memory (and should not be consfused with hard drive storage which is very much akin to a person's long term memory). Programs running on your computer use RAM to remember what it is they're doing. Here's an analogy:

• Analogy: Imagine you've been sent to the grocery store to buy dinner. Luckily, someone has provided you with a written-down list of things to get that's fairly long.
  
  So, you arrive at the store and start retrieving the items on your list. Lets say the first item on the list is Oreos (mmm...so good...), so you dutifully go to the junk food aisle and put a box of oreos in your bag. Now you look at the list again, but the first item is still Oreos (crossing things out with a pencil takes too much of your precious time). However, instead of putting yet another box of Oreos into your cart, you head over to another aisle and get a jar of peanut butter (the second item on the list). How did you know that you had already gotten the Oreos? You remember that you already had, of course! Likewise, once you put the peanut butter in your basket, you'll move on to the third item, having remembered that you've already retrieved the first two.
  
  In this analogy, the short-term memory that you used to remember how far you had progressed down your grocery list is very similar to a computer's RAM and how it is used. I say "short-term" because you probably won't remember that information for long--in fact, you'll probably forget it as soon as you leave the grocery store. The more permanent shopping list will stick around for much longer, however: in this way it is very like your computer's physical storage (a.k.a. hard drive storage).
  
  But why didn't you just mark your place on the list with a pencil? The problem is that this takes time: it takes a split second to make a mental note, but a few seconds to get out your pencil and scribble some marks. A few seconds might not be important to the average human being, but to a computer this kind of delay is unacceptable: RAM can read and write information much, much faster than your hard drives can, so it's used in applications where read/write speed is critical for performance.

• Real-life example: Open Microsoft Word and type a few sentences in a new document. At the moment, these sentences are stored in your system memory (RAM). This is nice, because your computer can keep adding this kind of information to RAM faster than you can type it; as soon as you type a letter, it should appear on the screen with no perceptable lag in between. Unfortunately, as soon as you turn off your computer, this information vanishes because RAM can only store information while it is receiving power. You're probably familiar with the process that will move this information into permanent storage: just go to File > Save. This action copies whatever information your RAM was storing onto your hard drives, where it will remain until you personally choose to delete it. Note that any subsequent changes you make to the file will be stored in RAM first, and copy of the current version will only moved into permanent storage when you save (although Word auto-saves for you every few minutes).
  
  Okay, so why doesn't you computer just save to your HDD in one step and cut out the "middle man," you ask? The problem is that, while hard drives are permanent and can store much, much more information that RAM can, they are also much, much slower*. If your computer had to save to your hard-drive every time you typed a letter, you would have to wait a while (probably on the order of a half-second (optimally) up to 5 seconds if the HDD disks have to spin up) each time you typed a letter. That would be plain annoying, thus we have the RAM/hard drive relationship.

*High-end RAM transfers data at about 3.2GB/second, while the best hard drives out there can only manage ~150MB/second.