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View Full Version : Why G751JT Is only Memory Single channel ?



x7007
01-05-2015, 03:39 AM
Shouldn't it be Dual mode for best performance ? Single is really crap,,, there are other laptops which has it, why shouldn't a $1800 laptop won't ?

Edweird
01-05-2015, 12:03 PM
Shouldn't it be Dual mode for best performance ? Single is really crap,,, there are other laptops which has it, why shouldn't a $1800 laptop won't ?

Ehm...what is your spec? 8GB is 1 8GB stick, 12GB is 8+4, 16 is 8+8, 24 is 8+8+8 and 32 is 8+8+8+8. I assume you have an 8GB version? Usually for memory to run in Dual Channel it has to at least have matching capacities, which has nothing to do with the laptop. 8+4 and 8+8+8 configurations have this weird channel and a half FLEX thing that basically makes some part of the memory run at dual channel speeds while some of it is held down at single channel speeds. (But I'm not sure the HM87 chipset or indeed this motherboard supports that.)

It also depends on what slots the memory is in. Even if it wasn't just 1 stick of 8gb but 2 sticks of 4gb they would have to be in the correct slots i.e 1 and 3 or 2 and 4. If you had a 8GB stick in yours when you bought it and added another to user accessible side, that would be single channel because the user accessible slots are 1 and 3. The ones inside are 2 and 4.

It clearly says right here on the forums for ASUS G751 buyers that if you want to run a 32gb configuration you MUST buy a model with at least 16gb because they only come in 8gb stick sizes (in some countries there is a 8+4 options) unless you want to void your warranty by opening the laptop up and changing it that way.

x7007
01-05-2015, 06:26 PM
Ehm...what is your spec? 8GB is 1 8GB stick, 12GB is 8+4, 16 is 8+8, 24 is 8+8+8 and 32 is 8+8+8+8. I assume you have an 8GB version? Usually for memory to run in Dual Channel it has to at least have matching capacities, which has nothing to do with the laptop. 8+4 and 8+8+8 configurations have this weird channel and a half FLEX thing that basically makes some part of the memory run at dual channel speeds while some of it is held down at single channel speeds. (But I'm not sure the HM87 chipset or indeed this motherboard supports that.)

It also depends on what slots the memory is in. Even if it wasn't just 1 stick of 8gb but 2 sticks of 4gb they would have to be in the correct slots i.e 1 and 3 or 2 and 4. If you had a 8GB stick in yours when you bought it and added another to user accessible side, that would be single channel because the user accessible slots are 1 and 3. The ones inside are 2 and 4.

It clearly says right here on the forums for ASUS G751 buyers that if you want to run a 32gb configuration you MUST buy a model with at least 16gb because they only come in 8gb stick sizes (in some countries there is a 8+4 options) unless you want to void your warranty by opening the laptop up and changing it that way.

I have the 16Gb version 8x2

Edweird
01-05-2015, 06:35 PM
I have the 16Gb version 8x2

And they're both on the inaccessible side? Neither of the sticks are on the underside where you can access them? From what I've seen from the slot layout, those slots give you dual channel speeds. What method did you use to get this result? Have you tried running memtest86?

hmscott
01-05-2015, 08:36 PM
Shouldn't it be Dual mode for best performance ? Single is really crap,,, there are other laptops which has it, why shouldn't a $1800 laptop won't ?

x7007, what tool did you use to check? CPU-Z memory tab will tell you. You have a 2 x 8GB configuration, it should be Dual Channel, like this:

45090

CPU-Z download, Asus ROG skin, Customized version (on right column)
http://www.cpuid.com/softwares/cpu-z/versions-history.html