A8N-SLI DELUXE 4 x 512 Dual Channel Memory Speed

[pc]

I wish Nvidia &/or ASUS would make the requirements for operating in
Dual Channel memory mode a bit easier to understand.

I've taken great care configuring my A8N-SLI Deluxe system, & in
particular, the memory, so that I could get Dual Channel to work ok.
It's running 1006 BIOS with XP Pro SP2, all the latest and greatest
patches.

From a document entitled "A8N-SLI Qualified Vendors List (QVL)" I

downloaded from the ASUS site on 2/13/2005, they note that the
following memory: (512MB CORSAIR VS512MB400 VALUE seLecT) in a double
sided configuration with VS32M8-5 chips is supported in all the
following modes:

@@@@@@@@@@@@@@@@@@@@@@@@
Note:
A* : Supports one module inserted in any slot as Single-channel memory
configuration
B* : Supports one pair of modules inserted into eithor the blue slots
or the black slots as one pair of Dual-channel memory configuration
C* Supports 4 modules inserted into both the blue and black slots as
two pairs of Dual-channel memory configuration
@@@@@@@@@@@@@@@@@@@@@@@@

I originally purchased 2 x 512 MB, inserted them in DIMM_A1 and
DIMM_B1, and it auto configured to 400 MHz Dual Channel. Great!

I had an opportunity this week to purchase two more identical boards,
delivered, from Newegg for less than $100. Cheap! When I plugged them
in, the system configured them to 333 MHz Dual Channel. Booo! I
manually configured them to 400 MHz and they seem to be working fine.

It's interesting that Sandra Pro 2002.6.8.97 won't benchmark the memory
after I went from 2 to 4 boards.

The manual (Rev. V2 of 11/04) in section 2.4.2 notes "double sided x16
memory chips are not supported in this motherboard. The Corsiar site
states that VS512MB400's are 64Mx64, so I guess that doesn't apply.

->> Any observations on why the system auto configured these to 333
MHz?

tanks.

pc

 

[Paul]

I wish Nvidia &/or ASUS would make the requirements for operating in
Dual Channel memory mode a bit easier to understand.

I've taken great care configuring my A8N-SLI Deluxe system, & in
particular, the memory, so that I could get Dual Channel to work ok.
It's running 1006 BIOS with XP Pro SP2, all the latest and greatest
patches.

downloaded from the ASUS site on 2/13/2005, they note that the
following memory: (512MB CORSAIR VS512MB400 VALUE seLecT) in a double
sided configuration with VS32M8-5 chips is supported in all the
following modes:

@@@@@@@@@@@@@@@@@@@@@@@@
Note:
A* : Supports one module inserted in any slot as Single-channel memory
configuration
B* : Supports one pair of modules inserted into eithor the blue slots
or the black slots as one pair of Dual-channel memory configuration
C* Supports 4 modules inserted into both the blue and black slots as
two pairs of Dual-channel memory configuration
@@@@@@@@@@@@@@@@@@@@@@@@

I originally purchased 2 x 512 MB, inserted them in DIMM_A1 and
DIMM_B1, and it auto configured to 400 MHz Dual Channel. Great!

I had an opportunity this week to purchase two more identical boards,
delivered, from Newegg for less than $100. Cheap! When I plugged them
in, the system configured them to 333 MHz Dual Channel. Booo! I
manually configured them to 400 MHz and they seem to be working fine.

It's interesting that Sandra Pro 2002.6.8.97 won't benchmark the memory
after I went from 2 to 4 boards.

The manual (Rev. V2 of 11/04) in section 2.4.2 notes "double sided x16
memory chips are not supported in this motherboard. The Corsiar site
states that VS512MB400's are 64Mx64, so I guess that doesn't apply.

->> Any observations on why the system auto configured these to 333
MHz?

tanks.

pc

Really, the answer to this question belongs in AMD's lap, but
their modular documentation system leaves a lot to be
desired. The reason this is all up to AMD, is the memory
controller lives on the processor, so the characteristics
of the memory drive capability are owned by the processor.
Whether a Nvidia or a Via chipset is used, the chipset has
nothing to do with memory (on Athlon64/Opteron boards).

The configurations that will work:

2x512MB dual channel - DDR400, Command Rate = 1T
4x512MB dual channel - DDR333, Command Rate = 1T or
DDR400, Command Rate = 2T

A previous poster noted better benches with DDR400 2T
when using four sticks. If you try DDR400 1T with four
sticks, you will likely see memory errors. (I'm still
waiting for Anandtech to test the new Venus/SanDiego,
to see if there has been any performance improvements
when using four sticks. This issue likely won't change,
but perhaps the level of overclock possible on the memory
bus will change.)

Most commodity 512MB sticks are 16 chips of 32Mx8 each.
Those are x8 chips. The more expensive single sided
DIMMs are 8 chips of 64Mx8 each, again suitable for use
with the motherboard. I am not aware of a construction
of 512MB sticks involving x16 chips. (If they existed,
it would take 8 chips of 32Mx16, which would likely be
even more expensive than any other option, so
fortunately, no weasel memory makers will try it.)

For highest performance, you would want 2x1024MB double
sided DIMMs, running at DDR400 1T. They would be 16 chips
of 64Mx8 construction and would not be cheap. I think
Corsairmicro has some suitable ones, as do a number of
the other major makers. Be careful not to buy any
"stacked" 1GB modules from Pricewatch, as the "stacked"
configuration has higher loading than a module using proper
64Mx8 chips. If the advert mentions operation only works with
certain chipsets, that is a sign the modules are "stacked".
A low price is also a good indicator of bad stuff.

Paul

 

[3200+]

Really, the answer to this question belongs in AMD's lap, but
their modular documentation system leaves a lot to be
desired. The reason this is all up to AMD, is the memory
controller lives on the processor, so the characteristics
of the memory drive capability are owned by the processor.
Whether a Nvidia or a Via chipset is used, the chipset has
nothing to do with memory (on Athlon64/Opteron boards).

The configurations that will work:

2x512MB dual channel - DDR400, Command Rate = 1T
4x512MB dual channel - DDR333, Command Rate = 1T or
DDR400, Command Rate = 2T

A previous poster noted better benches with DDR400 2T
when using four sticks. If you try DDR400 1T with four
sticks, you will likely see memory errors. (I'm still
waiting for Anandtech to test the new Venus/SanDiego,
to see if there has been any performance improvements
when using four sticks. This issue likely won't change,
but perhaps the level of overclock possible on the memory
bus will change.)

Most commodity 512MB sticks are 16 chips of 32Mx8 each.
Those are x8 chips. The more expensive single sided
DIMMs are 8 chips of 64Mx8 each, again suitable for use
with the motherboard. I am not aware of a construction
of 512MB sticks involving x16 chips. (If they existed,
it would take 8 chips of 32Mx16, which would likely be
even more expensive than any other option, so
fortunately, no weasel memory makers will try it.)

For highest performance, you would want 2x1024MB double
sided DIMMs, running at DDR400 1T. They would be 16 chips
of 64Mx8 construction and would not be cheap. I think
Corsairmicro has some suitable ones, as do a number of
the other major makers. Be careful not to buy any
"stacked" 1GB modules from Pricewatch, as the "stacked"
configuration has higher loading than a module using proper
64Mx8 chips. If the advert mentions operation only works with
certain chipsets, that is a sign the modules are "stacked".
A low price is also a good indicator of bad stuff.

Paul

Great post Paul. I think most users running A64 Dual Channel will find that
clear enough.

 

[pc]

Thanks for your reply.

I guess I just don't have a good grip on memory chip configurations.
Clearly, if my modules are 512 MB and have 16 chips, they must be
32Mx16. What does Corsair's designation of "64Mx64" mean?

tx

pc

 

[Paul]

Thanks for your reply.

I guess I just don't have a good grip on memory chip configurations.
Clearly, if my modules are 512 MB and have 16 chips, they must be
32Mx16. What does Corsair's designation of "64Mx64" mean?

tx

pc

IMHO it means nothing

If you multiply out the numbers, you get 512MB of memory, so
I guess the spec isn't complete information free, but in
terms of telling us some useful information, I don't see the
point of even bothering to mention it.

It is too bad that a compact notation like (16)x32Mx8 is not
more popular.

Paul