Dual Channel Question

[Fizban]

I recently ordered a laptop that has 12 GB of DDR3L, specifically 3, 4 GB DIMMS. Will all 12 GB be running in single-channel?

Would it be in my best interest to remove one DIMM so it is merely 8 GB with a 2x4 config until I get a 4th DIMM to make it be 4x4?

I recall hearing several years ago in reference to older motherboards that 3 DIMMS could not run in dual-channel, but I wasn't sure if that was still the case.

edit: I assume anyway the only options are single-channel or dual-channel anyway. Triple-channel would be just peachy, but as far as I am aware no laptops motherboards and memory controllers support triple-channel?

 

[cheesy999]

I recently ordered a laptop that has 12 GB of DDR3L, specifically 3, 4 GB DIMMS. Will all 12 GB be running in single-channel?

Would it be in my best interest to remove one DIMM so it is merely 8 GB with a 2x4 config until I get a 4th DIMM to make it be 4x4?

I recall hearing several years ago in reference to older motherboards that 3 DIMMS could not run in dual-channel, but I wasn't sure if that was still the case.

edit: I assume anyway the only options are single-channel or dual-channel anyway. Triple-channel would be just peachy, but as far as I am aware no laptops motherboards and memory controllers support triple-channel?

Just leave it in there, the performance difference will likely be 0.1% at most, and there are some special interleaving techniques on laptop processors that work on 3 dimms (although not quite as fast as having 2)

 

[Kreij]

IMO, unless you are benching or running something that requires screaming fast RAM, more RAM is better than faster RAM.

 

[Fizban]

The assumption that no laptops support triple-channel, and that 3 DIMMS will run in single-channel are both correct though?

 

[Jstn7477]

Intel and AMD have both been able to do a sort of pseudo dual channel for a couple years now. My Toshiba X205-SLi4 back in the day had a 2GB and a 1GB stick of DDR2 that ran in symmetric dual channel mode with a PM965 chipset and a Core 2 Duo T8100. My dad's ASUS laptop with an i7-720QM has 3 DIMM slots (4+2+2GB) and it runs fine, so I wouldn't be too worried about it.

 

[cheesy999]

The assumption that no laptops support triple-channel, and that 3 DIMMS will run in single-channel are both correct though?

The whole dual/single channel thing gets a bit complicated with modern chips, just put all the ram you have in

If you really want to get technical, what processor does it have?

 

[Fizban]

The whole dual/single channel thing gets a bit complicated with modern chips

Not sure of the exact motherboard model since the laptop hasn't arrived yet, but the laptop is a Toshiba Qosmio, and has a new haswell i7-4700MQ, I was hoping the haswells might have triple-channel support, but seems that that is only the case for the desktop haswells, and even then only some of them.

On a slightly unrelated note, the new laptop has 1600 mhz DDR3L, there any real difference between DDR3L and DDR3 I should expect to see other than slightly better battery life?

 

[cheesy999]

Not sure of the exact motherboard model since the laptop hasn't arrived yet, but the laptop is a Toshiba Qosmio, and has a new haswell i7-4700MQ, I was hoping the haswells might have triple-channel support, but seems that that is only the case for the desktop haswells, and even then only some of them.

On a slightly unrelated note, the new laptop has 1600 mhz DDR3L, there any real difference between DDR3L and DDR3 I should expect to see other than slightly better battery life?

The first 8gb of physical memory will be done as dual channel ram on two of the sticks, if this fills up the processor will use the last 4 gb as single channel ram independently, so you have nothing to lose by keeping the extra stick in (if you want to find out more, section 2.1.3 here - see Intel Flex Memory Technology Mode)

It's only power usage really