RAM Question...

[Linux Rockz]

I have an A7N8X-E Deluxe board that supports dual channel, at present I
have 2x512Mb PC3200 sticks in, one in slot A1 and the other in B1 ...I
also have a spare 256Mb PC3200 stick, I was wondering if I could use that
and still make use of the dual channel, or would it clock it down? If this
is possible, which slots should I be putting which sticks into?

 

[Ben Pope]

I have an A7N8X-E Deluxe board that supports dual channel, at present I
have 2x512Mb PC3200 sticks in, one in slot A1 and the other in B1 ...I
also have a spare 256Mb PC3200 stick, I was wondering if I could use that
and still make use of the dual channel, or would it clock it down? If this
is possible, which slots should I be putting which sticks into?

Dual Channel doesn't affect the clock rate, so there would not be any
"clocking it down".

Dual Channel means two channels. If there is some RAM in each channel, you
can use Dual Channel.

Leave the two 512MB DIMMS in separate channels and just add the 256 in
wherever.

Ben

 

[Paul]

Dual Channel doesn't affect the clock rate, so there would not be any
"clocking it down".

Dual Channel means two channels. If there is some RAM in each channel, you
can use Dual Channel.

Leave the two 512MB DIMMS in separate channels and just add the 256 in
wherever.

Ben

If you want to test the difference, get a copy of memtest86
from memtest.org and test the memory before adding the stick
and then test after adding the stick. There is a memory
bandwidth number at the top of the display. You should
be able to judge the difference with that.

As a bonus, you get to test whether the whole 1280MB is sound
or not

Paul

 

[DaveW]

If you add the third stick you will not be able to use the dual channel
feature.

 

[Ben Pope]

If you add the third stick you will not be able to use the dual channel
feature.

You continue to spout this rubbish every time the question is asked. You
continue to be corrected. There are loads of examples of people here and
elsewhere that have asymmetric memory channel configurations and it works.

Why don't you just read the last paragraph on page 7 of this document:

http://www.nvidia.com/object/LO_20021105_7263.html

"Both of the memory controllers on DualDDR are functionally identical with
all control and timing parameters independently programmable. This
flexibility allows the users to populate up to three asymmetric DIMMs in any
organization, size and speed. DualDDR simply adjust to the lowest common
density that will facilitate 128-bit bandwidth, allowing a wide variety of
different DIMM combinations to operate reliably regardless of the individual
density and latency characteristics. DualDDR also doubles the addressable
memory space to 3GB. End-users now can populate higher density DIMMs, up to
1GB each, to utilize the entire 3GB memory address map. This large memory
map allows more application and audio, video streams to coexist without
conflicts. DualDDR also incorporates three memory address buses to reduce
loading and to ensure all three DIMMs operate stably at very high data
rates."

Or, why don't you just try it?

But to continue to say that it will not work, every time this question is
asked is ridiculous, when it WILL work.

Ben

 

[Linux Rockz]

But to continue to say that it will not work, every time this question is
asked is ridiculous, when it WILL work.

Ben

Sorry if I've repeated the question again, my usenet server only keeps
stuff for 5 days before deletion...

so, you're saying it is possible to run 2x 512Mb PC3200's as well
as a 256Mb PC3200, but which slots are recommended for each stick?

Also, how would I know if the dual channel feature is functional on my
board, I'm running XP Pro on that machine, in the system properties it
only reports 1Gb RAM, nothing regarding throughput speeds?

 

[Ben Pope]

Sorry if I've repeated the question again, my usenet server only keeps
stuff for 5 days before deletion...

My reply above was to DaveW.

If you want a history of newsgroup posting you will find pretty much ALL of
them here:

http://groups.google.com

so, you're saying it is possible to run 2x 512Mb PC3200's as well
as a 256Mb PC3200, but which slots are recommended for each stick?

Yeah. Just put the 256MB in the middle slot, it'll be fine. That will
ensure that you have 768MB on one channel and 512MB on the other channel -
as close a balance as you can.

Also, how would I know if the dual channel feature is functional on my
board, I'm running XP Pro on that machine, in the system properties it
only reports 1Gb RAM, nothing regarding throughput speeds?

The BIOS will inform you at POST.

The DIMM slot closest to the CPU, and the middle DIMM slot, will form 1
channel. The DIMM slot furthest from the CPU is the second channel. As
long as you have at least one DIMM in each channel you will have Dual
Channel, on that board.

I always recommend setting the timings by hand (pick the biggest number for
each timing), but especially in Dual Channel config with non "matched"
DIMMS. Most of the time you won't have problems, but occasionally the BIOS
can get confused and set them in a fashion that runs one or more DIMMs out
of spec.

Here is an example, insert the numbers appropriately for your RAM.

PC3200 512MB 7-2-3-2 timings (2 DIMMS)

PC3200 256MB 11-3-2-3 timings

If that was your timings (pretty unlikely!) I'd suggest setting your timings
in the BIOS to 200MHz, 11-3-3-3 so as not to run any of it out of spec.

Ben

 

[Doug Ramage]

My reply above was to DaveW.

If you want a history of newsgroup posting you will find pretty much ALL of
them here:

http://groups.google.com


Yeah. Just put the 256MB in the middle slot, it'll be fine. That will
ensure that you have 768MB on one channel and 512MB on the other channel -
as close a balance as you can.



The BIOS will inform you at POST.

The DIMM slot closest to the CPU, and the middle DIMM slot, will form 1
channel. The DIMM slot furthest from the CPU is the second channel. As
long as you have at least one DIMM in each channel you will have Dual
Channel, on that board.

I always recommend setting the timings by hand (pick the biggest number for
each timing), but especially in Dual Channel config with non "matched"
DIMMS. Most of the time you won't have problems, but occasionally the BIOS
can get confused and set them in a fashion that runs one or more DIMMs out
of spec.

Here is an example, insert the numbers appropriately for your RAM.

PC3200 512MB 7-2-3-2 timings (2 DIMMS)

PC3200 256MB 11-3-2-3 timings

If that was your timings (pretty unlikely!) I'd suggest setting your timings
in the BIOS to 200MHz, 11-3-3-3 so as not to run any of it out of spec.

Ben
--

I am running in Dual Channel mode with 3 x 512Mb sticks (one of which has a
different memory speed).

 

[Linux Rockz]

I got all the sticks in and it's still running in dual channel mode,
although it's only reporting 332Mhz which is also the speed of my CPU's
FSB, I assume this is correct for the RAM & FSB to be matched?

thanks for everyone's help so far,

Ben, your site is really helpful too, thanks again.

 

[Ben Pope]

I got all the sticks in and it's still running in dual channel mode,
although it's only reporting 332Mhz which is also the speed of my CPU's
FSB, I assume this is correct for the RAM & FSB to be matched?

Generally, on Force2, yes.

thanks for everyone's help so far,

Ben, your site is really helpful too, thanks again.

No problems.

Ben