If I understand correclty, the RAM one buys must be of the same kind as the rest of the RAM currently in the motherboard. So the question is, is there any way of finding out what kind of RAM to buy short of opening up the case and checking? Is there a program that can help? A site where you can submit your model no# and it'll tell you? Anything?

If not, what do I look for when I open up the case?

^_^; Thanks!

I'm unaware of any program which will do this. Usually, the way things work is that this info is obtained by the BIOS, typically over an I2C interface. This info is called the SPD info, and is used by the BIOS to program the memory controller so that it can access the RAM correctly. It's the BIOS does this before any attempt is made to actually use the RAM.

Once the OS is running, you don't need to muck with it, as it is using RAM already.

Which isn't to say that there's no such program out there to do this; but doing a google search for SPD programming might turn up an answer.

If you do obtain these values, then you can compare them against the datasheet of the RAM which you want to purchase to see if it is compatible.

But honestly, just getting the Manufacturer and model number off of the chips is probably easier and quicker.

What you're looking for is either the above info for the DIMM; but better yet are the numbers on the chips themselves. From that you should be able to pull up a datasheet on the new RAM that you're thinking about buying.

Even easier is to put the above information in an email, and send it to the folks over at mushkin.com. They are usually superb at figuring this stuff out.

Note: I have no relationship with them other than as an extremely satisfied customer. They once even put together a custom DIMM for an obscure system of mine.

The critical thing to do is to run memtest86 when you get your new RAM. This is now an option on the current RH Fedora install CD's. I like to test out my own memory for a couple days before I consider it as "good"