Dual Channel with 3 sticks of RAM?

[guilliam]

---

Using Dual Channel

Dual Channel requires at least two modules for operation. It is recommended that the modules you use be of the same size, speed, arrangement etc. Dual Channel is optional on the original nforce2 motherboards and nforce2 ultra400. You can choose to run in single channel mode on these motherboards. Nforce2 400 boards are singe-channel only. Most dual channel capable nforce2 motherboards come with three slots. On these motherboards the first memory controller controls only the first slot (or the slot by itself), while the second memory controller controls the last two slots (which are usually closer together). Name them slots 1, 2 & 3 respectively. To implement Dual Channel, it is necessary to occupy the slot 1 (channel 0) and either one of the two slots that are closer together, slots 2 or 3 (channel 1). The entire config would be running in 128 bit mode.

You can use three modules in Dual Channel Mode, by filling the third unoccupied slot. With three sticks, slots 1 remains as channel 0 while slot 2&3 become channel 1. To maintain 128-bit mode, with all three slots filled, each channel must have an equal amount of memory. For example, slots 1 should be filled with a 512 Mb module, while slots 2 & 3 are populated 256 Mb modules. If you were to use three modules of the same size, then only the first two modules would be running in 128 bit Dual Channel Mode. Example, using 3x 256 Mb modules will have the first 512 Mb running in 128 bit Dual Channel mode, while the remaining 256 Mb will be in 64-bit Single Channel mode.

Intel dual-channel systems are different. The have either two or four slots, and to run dual channel mode must have either one or two pairs of (hopefully) matching modules. Running three modules on a P4 system will force it to run in single channel mode, and is therefore to be avoided.

but since in your case youre using an amd setup.. it will work ~winks~

[XReaLm]

in my case it works in dual mode.. i had 3 x 512MB of memory DDR333
Motherboard: Epox 8RDA3G nvidia nforce 2 ultra 400

::Channel 0::
512MB DDR333

::Channel 1::
512MB DDR333
512MB DDR333

[AMD_infinium05]

wow... 1.5gb kewlio

[MRSWAVE]

Dual channel feature highly needs an identical memory modules to avoid errors. Mix memory specs still works fine but is not advisable. This feature will run if there's at least two or more memory sticks are installed.

just my two cents!!!!

[jamamp;jem]

same specs of SDRAM is better in dual mode with 2 channel running::

Channel 0::
512MB DDR333

::Channel 1::
512MB DDR333
512MB DDR333

channel1 only @ dual mode

[fatsu]

if mag dual channel ka bay much better if ang mga paired na modules ang imong paliton.

[jiro]

3 sticks in dualmode?

hmm.. not that i know of.

as long as all mem has pairs it will work at dual mode.

if not then it only works as normal...

it will never work in dual mode with 3 rams.

and its not possible and logical.

dual channel will use 2 rams as if its running 1 - with more speed and bandwidth and sort of things. adding 1 more ram, will not allow the cpu to use the "other single ram" to allocate memory as it does not have the same speed.

sample -
2rams at 800mhz
1ram at 400mhz

See my point at 800 and 400mhz? they dont have same speed. (if ever this works, the cpu will simply wait for the other ram(400mhz) then continue execution and therefore uses only 400mhz.

my 2 cents... 3 ram cannot dual ram. even if it does it will only use the slowest ram speed.

same goes if you have 2 rams - 1 is DDR400 and the other is DDR333, then CPU uses only DDR333 as top speed.

[jiro]

2rams of DDR400 - in dual channel this will run at 800MHZ

3rams of DDR400 - in dual channel, the 1dual will run at 800mhz,
IF YOU have the 3rd ram say 512 DDR800, then it will run at 800MHZ!!!

if not
then it will run at the slowest speed.
your computer sees it this way
1 512mb (2x256) at 800mhz (peak @ 6400KB/s)
1 512mb (1x512) at 400mhz (peak @ 3200KB/s)

therefore computer will uses 400mhz ONLY (peak @ 3200KB/s).
you have dual channel enabled.


again
IF YOU have the 3rd ram say 512 DDR800, then it will run at 800MHZ!!!
therefore its ok to use 3 rams.

[jiro]

grss, for your info,

the AMD Athlon 64 series with the 754 socket does not support dual channeling, but the newer 939 socket does.

for your reference, check this out.
http://www.digit-life.com/articles2/...plus-s939.html


i've research about your sempron,
its a socketA, and yes it supports dual channel... but with 3 slots?

what is your Mobo FSB?

i guess more ram is better, what is your Mobo FSB? if its 400mhz or <800mhz then 3 rams is ok, and dual channel, IMHO, is useless for that setup. its ok to have 3 rams.

dual channel is best for FSB twice the DDR speed.
for DDR400, MOBO with 800fsb is best.
for DDR333, Mobo with 666mhz is best(if there is one.)
for DDR266, Mobo with 533mhz is best.

.....

just found anothere results in forums.
"You will receive no noticable improvement running dual channel"
well i guess its ok to have 3 rams.

[[DSX]]

@jiro: you seem to know a lot about dual channel coz you got long posts.... i dont know where you learned those but dual channel does not mean doubling mem freq. thus:
2xDDR400!=800Mhz in dual mode but still in 400Mhz --this time running in 128-bit rather than only 64bit in normal mode. and yes 3 rams at dual channel mode works! (not all boards support this.. if you have 4 mem slots.. most probably it wont work in dual channel)