Is there any way to find out which memory slots are for which memory channel(laptop)?

[dguy6789]

I have an Asus G73JH laptop that has four memory slots and two memory channels. Three of the memory slots are easily accessible and one of them is on the other side of the motherboard and is so difficult to reach that I'd rather not bother trying(involves taking the laptop pretty much completely apart including messing with stuff that isn't meant to be disassembled that may not be able to be put back together right afterwards). This hard to reach slot has a 2GB stick of RAM in it already. The other three slots have two 2GB sticks and a 4GB stick.

What I would like to do is find out which of the slots goes to which memory channel so that I can upgrade one of them to a 4GB stick and have a fully symmetric dual channel 12GB ram configuration with 6GB per channel since I'd rather not run 8GB symmetric or 14GB asymmetric.

I'm aware the performance difference is negligible this is entirely an OCD thing.

Any ideas on how to find out would be greatly appreciated.

 

[MontyAC]

Does the manual show that?

 

[dguy6789]

It tells me which ones are 1, 2, 3, and 4 but it doesn't say anything about the channel. On desktop computers I've seen the channels split up all kinds of ways like 1/2 3/4, 1/3 2/4, 1/4 2/3, etc.. so this doesn't really give me a solid answer.

 

[MontyAC]

Try contacting ASUS support.

 

[Eeqmcsq]

Does the POST or BIOS tell you if you're in single/dual channel mode?

Edit - That is, you could pull out 2 of the sticks and see what channel mode the POST or BIOS reports. This way, you can find out which of the 3 easy-to-reach slots is paired with the hard-to-reach slot.

 

[dguy6789]

Great idea E. The bios itself doesn't show me if it is in dual channel or not but CPUZ does. I'll use this to figure out which slots go to which channel. Thanks!

 

[dguy6789]

Memory slot 1, 3, and 4 are the ones that are easily accessible. Memory slot 2 is the one on the other side of the motherboard that I can't get to.

The system will not post at all with memory only in slot 2 for some reason. With a stick in slot 2 and 1 it boots into single channel mode. With a stick in slot 2 and 3 it boots into single channel mode. With a stick in slot 2 and 4 it does not post. With sticks in all 4 slots it boots fine and is in dual channel mode and detects all of the RAM capacity properly.

This seems quite odd. The bios is latest and all of the ram is good.

 

[Schmide]

The spec page says only 8gb on some 4gb on others.

http://usa.asus.com/Notebooks/Gaming_Powerhouse/G73Jh/#specifications

DDR3 1066/1333 MHz up to 8GB (Intel® i7-720QM / i7-820QM platform)
DDR3 1066 MHz up to 4GB (Intel® Core™ i7-620M/ i5 / i3 platform)

 

[dguy6789]

That's wrong it supports 16GB. I've been running 10GB of 1333Mhz DDR3 for almost 2 years. Some people have upgraded it to the full 16 without issue as well on other forums.

 

[Eeqmcsq]

Memory slot 1, 3, and 4 are the ones that are easily accessible. Memory slot 2 is the one on the other side of the motherboard that I can't get to.

The system will not post at all with memory only in slot 2 for some reason. With a stick in slot 2 and 1 it boots into single channel mode. With a stick in slot 2 and 3 it boots into single channel mode. With a stick in slot 2 and 4 it does not post. With sticks in all 4 slots it boots fine and is in dual channel mode and detects all of the RAM capacity properly.

This seems quite odd. The bios is latest and all of the ram is good.

That's not just odd. That's a WTF IS GOING ON???

In any case, the most logical conclusion is that slot 2 is paired with slot 4, and since you'll still be using 4 sticks, you should be OK when you insert a second 4GB stick.

 

[dguy6789]

That's the conclusion I came to. I'm going to get in touch with Asus and see if they can give me a hard answer or not.

 

[Eeqmcsq]

I poked around the net and found someone else with the same odd behavior when testing with 2 sticks.

http://rog.asus.com/forum/showthread.php?12929-Asus-G73JH-only-Single-Channel-Mode

This guy misnumbered the slots in his 1st comment, but otherwise, he saw the same thing you saw: Slot 2 only = no boot. Slot 2 + 4 = no boot.

 

[dguy6789]

Probably just a flaw in the motherboard design I dunno. Not really an issue since I only plan to run 4 sticks anyway. I just wanna find out which channels they belong to. Sent Asus an email so we'll see if they can tell me.