A7N8X Dlx - dual mode question

[Petar]

I currently have 2 x 256 MB of Corsair T1 RAM working in double mode. I
would like to install another 512 MB in one module. If I do that would I
still have 512-512 double mode? Does somebody have this kind of
configuration working? I heard of some cheaper boards having problems with
this combination.

Tnx.

 

[D R Tester]

Put your 2*256Mb in slots 1 (nearest to cpu) and 3 (furthest from cpu) and
the 512MB in slot 2. Have this arrangement and is working fine, dual channel
mode really doesn't make a hugh difference on AMD based system (2-3%) unlike
Intel based systems.

Dom

 

[Paul]

Put your 2*256Mb in slots 1 (nearest to cpu) and 3 (furthest from cpu) and
the 512MB in slot 2. Have this arrangement and is working fine, dual channel
mode really doesn't make a hugh difference on AMD based system (2-3%) unlike
Intel based systems.

Dom

Maybe I'm missing something here, but if I look at a picture of
the motherboard, slots 1 and 2 (nearest the CPU) are wired together
and are on one channel. Slot 3 is furthest from the CPU and is on
the second channel. Then, the config you want is:

Channel 0 Channel 1

Slot 1 256MB Slot 3 512MB
Slot 2 256MB

That makes the amount of memory on each channel equal.
If the memory on the channels isn't equal, then for the
portion that isn't equal, the memory controller has
no choice but to fetch from only the one channel.
Equal stacks of memory on each pile should work best.

Unequal stacks of memory means the controller can run
in dual channel mode for the lower part of memory,
and single channel mode for the upper part of the
memory.

I wish someone would write a memory filling program
in Linux and test the various configurations, to
give some proof of what is what.

In any case, given that the bandwidth of the processor
bus is matched by the bandwidth of one DIMM running at
the same clock speed, dual channel mode might only help
fill the odd gap, or improve things when the odd
AGP texture transfer is happening.

Paul

 

[Doug Ramage]

Dom, that arrangement should not give you full dual channel - assuming the
above mobo.

Slots 1&2 = Channel 1, and slot 3 = Channel 2.

So it should be 256Mb sticks in slots 1&2 (Channel 1 = 512Mb) and a single
512Mb stick in slot 3 (Channel 2 = 512Mb).

 

[D R Tester]

It's commonly known that on the Asus A7N8X that : Slots 123= Single Channel
64bit. Slots 1-3 = dual channel 128bit slots 2-3 most people think that its
dual channel but its not on the ASUS!! 1-3 is only DC DDR.

Have a look at:

http://www.nexushardware.com/forums/showthread.php?threadid=21

 

[Ben Pope]

It's commonly known that on the Asus A7N8X that : Slots 123= Single
Channel 64bit. Slots 1-3 = dual channel 128bit slots 2-3 most people
think that its dual channel but its not on the ASUS!! 1-3 is only DC DDR.

Not true

http://www.nexushardware.com/forums/showthread.php?threadid=21

Not true.

Since when does some dude posting in a random hardware forum give an
athoritative answer?

If you read the chipset specs you will know that the 3rd DIMM cannot operate
in single channel if the other two are in dual channel, so that discredits
"Brian L" and "Extremeg177".

Seriously, why would that not be a valid combination on the Asus board? The
slots are wired to the chipset, the chipset does the dual channel... you
can't just "not implement it" on the board.

Dual Channel WILL result when you have at least 2 DIMMs, with one of them in
DIMM slot 3 (furthest from the CPU)

Ben

 

[D R Tester]

Thx for clearing it up Ben, so are we saying that slot 1+2 should equal 3
for dual channel operation?

Dom

 

[Petar]

Thx for clearing it up Ben, so are we saying that slot 1+2 should equal 3
for dual channel operation?

Dom,

have you rearranged your memory this way? Please post if you have and let
us know does it work in dual mode now... You are still the only one having
all needed hardware to proof this assumption

Petar

 

[Ben Pope]

Thx for clearing it up Ben, so are we saying that slot 1+2 should equal 3
for dual channel operation?

No, funnily enough I'm saying that "Dual Channel WILL result when you have
at least 2 DIMMs, with one of them in DIMM slot 3 (furthest from the CPU)"

Just to clarify that (if it's not clear enough), you DO NOT require the same
amount of RAM in each channel for dual channel.

Ben