I have a old Dell Inspiron 1300, has a stick of 256mb samsung ddr2-4200. On this sticker it says 1Rx16, I see this on all ram Ive searched and to what i know its a density indicator. My laptop can upgrade to 2gigs but im not sure whats compatible. I see ram say 1Rx8 1Rx16 2Rx8 2Rx16, how do i know what my laptop takes as for as this Rx reference?
You don't need to know that. It probably refers to how many chips they used on the RAM module to create the total size but the laptop doesn't "see" or "care" about this.
If your manual says you need DDR2-4200 that's mainly all you need to know.
However, often RAM is Dual Memory meaning you want two equal modules such as two 1GB modules (2x1GB); a single 1GB memory stick operates at HALF the speed of two sticks. You can sometimes get away with a different company if the latencies (i.e. 8-8-8-24) are the same but it's recommended to use the EXACT same type.
I appreciate the help, do you know of any instances that laptops or desktops have had any problems with mixing these Rx specs? Like Rx8 with Rx16? i was searching for ram on ebay and i saw a question about if it was 2Rx16 or 2Rx8 because this buyer only said his laptop could only take 2Rx8. So i said well... i guess its more than just looking for pc2-4200 u have to look for this Rx thing. thanks again