single channel ddr3 vs dual channel ddr3

I've got two 10 year old laptops and I'm upgrading the memory to 8GB. On Speccy it's currently reporting the RAM as

HP: DDR3 Single channel PC3-12800, 2 slots both used
Toshiba: DDR3 Dual channel PC3-10700 2 slots one used

I'm confused so please correct me if I am making the correct assertions below. BTW I'm buying the ram secondhand off of Ebay and not buying from e.g. Crucial as too expensive otherwise I would use their memory wizard and be done:

ASSERTIONS:

1. The HP has a single channel memory architecture on the MB but the Toshiba has dual channel architecture on it's MB.
2. Any DDR3 SODIMM will work so I could use PC3-12800 on either laptop using a 2 x 4GB config.
3. Dual and single channel refers to the MB design and not the physical structure of the memory sticks. But if the memory sticks are labelled dual channel it means that they are designed to work with second paired memory stick in the appropriate channel.

Many thanks for any help in setting me straight if reqd :)

Dual channel is a computer feature (MoBo+Chipset+CPU), not a memory feature.
Dual Channel is similar to RAID 0 on drives. On a Dual Channel, data is split ed into two parts, and one part is sent to one memory stick and the other part is sent to the other memory stick, almost doubling the memory speed seen by the computer.
To work well, the memory sticks should be same size, same speed, have same timings, and have same chipsets. In other words, they must be a matched pair.
You can use different memory sticks but the chances they don't work well are big.

On your description, something isn't right:

HP: DDR3 Single channel PC3-12800, 2 slots both used - It can be if the sticks are different
Toshiba: DDR3 Dual channel PC3-10700 2 slots one used - To have dual channel, there must be at least one pair of memory sticks.

If you don't want to have memory problems, make sure the two sticks are the same.
Use HWinfo to find the memory specs

Megahertz said:

Dual channel is a computer feature (MoBo+Chipset+CPU), not a memory feature.
Dual Channel is similar to RAID 0 on drives. On a Dual Channel, data is split ed into two parts, and one part is sent to one memory stick and the other part is sent to the other memory stick, almost doubling the memory speed seen by the computer.
To work well, the memory sticks should be same size, same speed, have same timings, and have same chipsets. In other words, they must be a matched pair.
You can use different memory sticks but the chances they don't work well are big.

On your description, something isn't right:

HP: DDR3 Single channel PC3-12800, 2 slots both used - It can be if the sticks are different
Toshiba: DDR3 Dual channel PC3-10700 2 slots one used - To have dual channel, there must be at least one pair of memory sticks.

If you don't want to have memory problems, make sure the two sticks are the same.
Use HWinfo to find the memory specs

That's a good point but it has only one memory stick and it seems to be working. I'll take the back off later but I'm assuming Speccy is correct so yes good spot :)


My other question would .... DDR3 SODIMM PC3-12800 work on either laptop using a 2 x 4GB config? Any ideas, I'm assuming it would.

Gusgf said:

That's a good point but it has only one memory stick and it seems to be working. I'll take the back off later but I'm assuming Speccy is correct so yes good spot :)


My other question would .... DDR3 SODIMM PC3-12800 work on either laptop using a 2 x 4GB config? Any ideas, I'm assuming it would.

If the two sticks of DDR3 SODIMM PC3-12800 are equal there should be no problem.
Run HWinfo on the Toshiba. It will probably show as single channel (dual channel capable)

Megahertz said:

If the two sticks of DDR3 SODIMM PC3-12800 are equal there should be no problem.
Run HWinfo on the Toshiba. It will probably show as single channel (dual channel capable)

Thank you again :)