PDA

View Full Version : RAM Slots Population Order?



JRd1st
11-29-2011, 02:44 AM
. . . or in other words, which slots are you supposed to put RAM in in order to maintain dual channel memory?

1,2 and 3, 4? 1,3 and 2,4 or . . .

Please don't tell me what you "think" or what "Asus usually does" I only want to know the facts for the G74, G73, and G53 notebooks so I can add this info to my New Drivers sticky (I'm going to have to rename that thing lol ) so there's a reference on this.

It's ridiculous that there is no hard info available on this subject...

dstrakele
11-29-2011, 02:50 AM
http://en.wikipedia.org/wiki/Dual-channel_architecture states:

"The memory modules are installed into matching banks, which are usually color coded on the motherboard."

They even have a picture of the color-coded memory slots.

Also:

"If the motherboard has two pairs of differently colored DIMM sockets (the colors indicate which bank they belong to, bank 0 or bank 1), then one can place a matched pair of memory modules in bank 0, but a different-capacity pair of modules in bank 1, as long as they are of the same speed. Using this scheme, a pair of 1 GB memory modules in bank 0 and a pair of matched 512 MB modules in bank 1 would be acceptable for dual-channel operation."

Brody likes to tear his machine apart at the drop of a hat - maybe he can tell us if there are some markings on the slots to differentiate them into banks or channels?

JRd1st
11-29-2011, 02:53 AM
That's true . . . on desktop boards but the notebook isn't like that. There's a whole thread where Chastity and others are conjecturing on this and I can't determine the "winner" lol

fostert
11-29-2011, 03:54 AM
Easy check: download and burn memtest86+ (get v. 4.20 which is for Sandy Bridge) onto a CD. Boot the CD, check your bandwidth (in MB/s; typically 14000-18000 MB/s). Change the DIMMs around into slots 1,2 for example; test again. You should notice a vast difference in bandwidth in a slot combination that that does not allow the dual channel pathway to the northbridge. You should be able to quickly peg the most favorable config this way.
Probably other ways to do this (maybe a Windoze utility?), but memtest86 is old-school and tried-and-true.

BrodyBoy
11-29-2011, 04:01 AM
Brody likes to tear his machine apart at the drop of a hat - maybe he can tell us if there are some markings on the slots to differentiate them into banks or channels?
Lol! The only markings I've noticed are that they're numbered 1 through 4, and the three modules that come in the 12Gb configs are installed in slots 1,2,3.

fostert
11-29-2011, 04:05 AM
My G74SX (CST1-CBIL; the Staples Canada version) came with 8GB of 1333MHz stuff (2x4GB Samsung sticks) which were in slots 1,3. My memory BW is ~14GB/s which is unachievable with a single channel config, so it must have been correctly set up for dual channel mode.

dstrakele
11-29-2011, 04:46 AM
+1 fostert!

JRd1st
11-29-2011, 01:49 PM
If you go by the numbers on the board, it's 1,2 and 3,4 but if you go by CPU-Z it's 1,3 and 2,4 (board 1,2 = 2 ,4 on CPU-Z) furthermore HWInfo reports 1,3 and 2,4 also, but board 1,2 = 1,3 on hwinfo! :confused:

This result is so totally Asus that I understand it, I think . . . . :confused: 1,3 and 2,4 makes sense to the motherboard and is typical Asus, but Asus named the slots 1,2 and 3,4 to be intuitive to people. I hope . . . .


Which means that CPU-Z is wrong? :confused:

fostert
11-30-2011, 02:16 AM
Ok, I'm gonna guess here...since My G74SX came with 2x4GB=8GB, I will assume that ASUS put those two sticks in correctly for dual channel mode, which seemed correct because of my good BW. Now we gotta guess what the slot numbers are that those two sticks were installed in. There are 4 slots for 4 DIMMs in the G74: each "outer" slot (closer to the bottom panel) is "stacked" on top of an "inner" slot (closer to the keyboard). The two sticks were installed in either "outer" slot, leaving both "inner" slots empty for upgrades.

So, whatever ASUS is calling those two "outer" DIMM slots are a "pair" that must be both filled to open a dual channel path to the CPU. Its been a while since I looked in there, so I don't know what those slots are labelled as there: 1 and 2?

JRd1st
11-30-2011, 02:22 AM
Yes! :D