Dual channel Question

[silverferro]

I have K7N2 Delta2 LSR board and have 3 memory slots only. At the moment I have 2 256MB DDR modules on each channel(256MB on purple slot 1 and another 256MB on green slot).

Now I want to upgrade my memory and my plan was to fit both 256MB modules on one channel(fill up both purple slots with 256MB each) and buy another single 512MB and install it on the other channel(green slot). So that both sides have equal capacity for dual channel to work.

But when I went to buy the 512MB module the shop keeper tells me this method won't work for dual channel since both modules need to be identical capacity to work.So he suggests I get 2 512MB modules for each channel and remove the 256MB. This does not make sence to me,as whats the purpose of having 3 slots when only 2 can be used.I belive the shop keeper is trying to con me into buying more from him.

Please advice if the method I suggested will work or is the shop keeper correct? Thanks

 

[imported_Phil]

He's not trying to con you, surprisingly.
With 2x 256MB sticks and 1x 512MB stick, the 256MB sticks will be running in dual channel, and the 512MB will be in single channel mode.

You need two identical (or similar) sticks to run dual channel, so ditching the 256MB sticks and getting two 512MB sticks will be the best plan. However, the difference between single and dual channel using real-world applications is in the order of 10%, so you may not notice the difference at all.

Hope this helps

 

[Lord Evermore]

Not entirely correct.


Sorry about the intrusion gang. This member has crossed the line. Goodbye!

AnandTech Moderator

 

[imported_Phil]

Originally posted by: Lord Evermore
Not entirely correct.

Get the hell out of here.

 

[Lord Evermore]

Far be it from me to give the guy the correct information.

 

[imported_Phil]

Originally posted by: Lord Evermore
Far be it from me to give the guy the correct information.

The correct information is a link to a Neochat thread?
Quit trolling.

 

[Fox5]

Nforce2 motherboards will run dual channel with just about any ram configuration, so long as 2 or more slots are filled. Nforce2 boards don't support true dual channel anyhow though, athlon xp cpus could never use it.
Not sure about athlon 64s, but modern P4s and Pentium-Ms have synchronous and asynchrounous dual channels modes, both are dual channel, both are faster than without, but sync is faster than async.

 

[chilled]

Originally posted by: Phil
He's not trying to con you, surprisingly.
With 2x 256MB sticks and 1x 512MB stick, the 256MB sticks will be running in dual channel, and the 512MB will be in single channel mode.

You need two identical (or similar) sticks to run dual channel, so ditching the 256MB sticks and getting two 512MB sticks will be the best plan. However, the difference between single and dual channel using real-world applications is in the order of 10%, so you may not notice the difference at all.

Hope this helps

That isn't true here, although it is the case with some chipsets.

I have a K7N2-L board (first version of the nforce 2 chipset) and I ran 1x512 + 2x256 fine in dual channel mode. The motherboard would report the dual channel mode at boot and the memory benchmarks confirmed this. I have no doubt that it is the same for the second version of the chipset as the BIOS has the same base.

FYI, I was using 2 x 256MB PC2100 @ PC2700 and 1 x 512 PC3200 @ PC2700. All Crucial.

 

[imported_Phil]

Originally posted by: chilled

Originally posted by: Phil
He's not trying to con you, surprisingly.
With 2x 256MB sticks and 1x 512MB stick, the 256MB sticks will be running in dual channel, and the 512MB will be in single channel mode.

You need two identical (or similar) sticks to run dual channel, so ditching the 256MB sticks and getting two 512MB sticks will be the best plan. However, the difference between single and dual channel using real-world applications is in the order of 10%, so you may not notice the difference at all.

Hope this helps

That isn't true here, although it is the case with some chipsets.

I have a K7N2-L board (first version of the nforce 2 chipset) and I ran 1x512 + 2x256 fine in dual channel mode. The motherboard would report the dual channel mode at boot and the memory benchmarks confirmed this. I have no doubt that it is the same for the second version of the chipset as the BIOS has the same base.

FYI, I was using 2 x 256MB PC2100 @ PC2700 and 1 x 512 PC3200 @ PC2700. All Crucial.

I'm probably going to stand corrected here, but this is from the manual:

Please note that the system will support dual channel DDR when you install
DDR modules on DIMM1(purple slot) and DIMM3(green slot), or DIMM2(purple slot)
and DIMM3(green slot).

Doesn't say anything about all three slots, but if you're saying that it works... well, okay

 

[silverferro]

thanks chilled, thats exactly what someone else said on a another forume as well. I have posted the question to MSI and waiting for their answer to finalise this matter once and for all.