Adding memory

bob6k

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Aug 14, 2007
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Possibly a stupid question, I'm looking to add an extra 2GB DIMM to my laptop. I've built loads of desktops and one thing that has been hammered into my head is you always have to use exactly the same type of RAM if you're using more than 1 DIMM.

But I've heard around that this isn't the case with laptops and you can use any combination of laptop RAM brands as long as they're the same DDR type. This seems ridiculous to me so can anyone confirm or refute this?

 
Generally true since each stick has it's own individual channel.
Dual channel & 1 stick of RAM per channel.
 
Notebooks typically only have two RAM slots. One is usually located in the back of the laptop which is generally accessible by removing two or four screws. The second slot is usually located underneath the keyboard which makes it a little more troublesome to access.

Normally both slots are occupied unless you specifically opted for a single RAM stick when you configured your laptop. Therefore, if you currently have 2GB of RAM using 2 x 1GB RAM sticks, then you need to buy 2 x 2GB RAM sticks to bring the total RAM up to 4GB.

I upgraded the RAM in my old IBM ThinkPad T40 with the same brand name (Crucial) and same CAS speed (2.5) as the ones which came with the laptop.
 

mavroxur

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Feb 8, 2009
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Some laptops have one slot under the keyboard (usually populated from the factory) and another free slot on the bottom of the laptop (behind a small removable cover). Others will have both slots behind the removable cover, or one under the keyboard and two behind the cover. It varies drastically. Some even have 4 under a cover (two stacked sockets).
 

Soph

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Nov 18, 2012
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I upgraded the RAM in my old IBM ThinkPad T40 with the same brand name (Crucial) and same CAS speed (2.5) as the ones which came with the laptop.[/quotemsg]


Sorry to cut in but I have a question you might be able to answer:

I have a thinkpad t42 with 512 MB (I guess 2x 256). I don't want a new one as this baby is well-loved.

But I really need to upgrade to 2-3 GB. Is this possible or even recommended? I read somewhere it could fry the CPU?

If it is possible, how do I find out what the brand name of the RAM is (you say this is crucial)?

Thanks.