SODIMM and DIMM in Dual Channel?

invento123

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May 5, 2018
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I got an older hp sff computer I've upgraded for a friend of mine to use. It still runs DDR2 with a core 2 quad. I got 4gb of ram in it but obviously this is not nearly enough for him and he wants more. I was recently given an old laptop with a 4gb stick of DDR2 SODIMM memory. My question is, if both the ram already in the HP computer he has and this laptop memory is the same speed, could I get a DDR2 SODIMM to DIMM adapter to allow it to run in dual channel, as in, 3 1gb sticks and the 4gb SODIMM stick? Any info would help!
 
Solution
Provided the adapter works, which i can't tell with certainty, you should be able to use all 4 sticks at once. However, you should note that RAM for your CPU can run in 2 ways: single channel, or double channel. Double channel is twice as fast as single channel, but it only works if the RAM sticks are equal by pairs. You have 3 of one type and 1 of another, so there's no way you can use the 4 in double channel mode. The fact that RAM might be faster in some configuration does not mean you will see great benefits from it, only if you have memory intensive apps, which most of us don't. I would recommend you to use all the RAM (7 GB) you have, even if it's not in dual channel mode. You need the capacity more than the speed, i would say.
I never thought of that... but apparently there are adapters (for example: http://www.ebay.com/bhp/sodimm-adapter). Note that the one i pasted here is for DDR3, so not the one you need, but you might be able to find it somewhere. I have never tested it, and there might be compatibility issues, so i really can not recommend it, but it might work. However, as for running the RAM in dual channel mode: that won't be possible, because you have odd numbers of similar dimms (3 of one type, 1 of the other). For dual channel to work, you need same sized pairs of dimms. Besides, depending on the operating system (OS) your friend uses, it might even not be useful: if the OS is 32 bits, it won't recognize more than 3.5 GB, you need a 64 bit OS to go beyond 3.5 GB.
 

invento123

Prominent
May 5, 2018
45
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Thanks for your response. He's running windows 7 64-bit. So perhaps if I cant run it with all 3 of the 1gb sticks, could I instead run it with 2 of the 1gb sticks in one channel and the 4gb SODIMM alone in the second channel (if that made any sense)?
 
Provided the adapter works, which i can't tell with certainty, you should be able to use all 4 sticks at once. However, you should note that RAM for your CPU can run in 2 ways: single channel, or double channel. Double channel is twice as fast as single channel, but it only works if the RAM sticks are equal by pairs. You have 3 of one type and 1 of another, so there's no way you can use the 4 in double channel mode. The fact that RAM might be faster in some configuration does not mean you will see great benefits from it, only if you have memory intensive apps, which most of us don't. I would recommend you to use all the RAM (7 GB) you have, even if it's not in dual channel mode. You need the capacity more than the speed, i would say.
 
Solution