RAM problem

[Adrian67]

I have just addes a 2 Go memory to the 2go I had so far. they're exactly the same kind, but the new one is not recognized, neither by the bios, not by Windows. "Physical address extension3 is now visible in My Computer/System. Who could give me explanations? Thank you.

Windows XP SP3
Motherboard: Asus P5N-E
Intel Quadcore Q6600 2.40 Ghz
Memory Transcend JM800 DDR2

[Sterling_Aug]

Take out the old stick and put the new one in its place and see if that works.

[Midknyte]

Are you sure it's not being detected? 32-bit versions of Windows will only show about 3.25GB of ram. Check your bios to see if the 4GB shows up there.

Check Best of Motherboards for the 4GB explanation.

[Adrian67]

I was wrong when I said both sticks are the same. In fact, one is a 4Go for dual channel DDr2 240P and the other is a2Go DDR2 240P. So I need advice. They seem to be incompatible, though The one I used before was the 4Go one that was, if I remember well, detected as a 2Go.

[Midknyte]

There is no such thing as "Dual channel" ram. They are sold in pairs, but they are no different from single sticks. Dual channel refers to the motherboard or cpu's memory controller. If it was sold as "4GB dual channel", then it was probably 2x2GB sticks.

Remove all the ram and test each stick individually.

[Adrian67]

Sorry, there's still something I don't understand. As one can see on the attached picture, the label on the stick I used before says "4GB for dual channel". The computer worked with this stick but it detected only 2Go. I understand I can't use it with a 2Go one because of the difference of capavity. But, just out of curiosity, can I ask why it did not detect the 4 Go? Thank you.

[Midknyte]

THERE IS NOT SUCH THING AS DUAL CHANNEL RAM. IT IS MARKETING.

4GB for dual channel would mean it's part of a kit. That means 2 dimms, 2GB each. It's not 1 4GB dimm.

[Adrian67]

I see now. Thank you. So in fact this stick is a 2Go one. Again there's this question: is it incompatible with the other stick that has this label:
2GB memory module STD 240P DDR2 800/5-5-5 [7T]?

[Sterling_Aug]

I see now. Thank you. So in fact this stick is a 2Go one. Again there's this question: is it incompatible with the other stick that has this label:
2GB memory module STD 240P DDR2 800/5-5-5 [7T]?

It must be if it doesn't work.

As always, I prefer to buy RAM at the crucial, corsair, or kingston web sites using each sites memory configuration utility. That way you ALWAYS get RAM that is guaranteed to work in your system. You should never buy cheap RAM just because you think it should work.

[Adrian67]

Very well. I did not know they had a configuration utility. I have tried it on both sites and it looks like it's very helpful. So I will follow your advice and thank you all for your help.