dimm1+dimm2 overclocks higher than dimm1+dimm3 for nforce2 MB?

If I use two modules of single bank memory (256 MB), I found that when I put them in dimm1+dimm2 (non-dual channel), I can overclock about few MHz (5-7) higher than putting them in dimm1+dimm3 (dual channel mode) on my A7N8X. The memory is running in SYNC mode with fsb.

I think it will hold true for modules with 2 banks (512 MB).

Also it overclocks better for 1 module with 1 bank (256 MB)
than 1 module with 2 banks (512 MB)
than 2 modules.

Do you come across similar situations, whether yes or no.


PS: I tested 2 modules 256 MB TwinMOS on A7N8X, I got 207 MHz on dimm1+dimm2, but 202 on dimm1+dimm3, both at 6-3-3-2, 2.6 V.

Also I got 211 MHz (6-3-3-2) with 1 module 512 MB in only dimm1.

This seems to be very normal.... Best OC with any board is usually with 1 stick. Enabling dual channel on NF2 boards seems to yeild the lowest FSB OC. I like to run DC so I will take a few Mhz lower than single channel.

For nforce2 MB whose FSB is just under 200 MHz, should give dimm1+dimm2 a try. Maybe that few MHz will just be able to get the fsb to 200 MHz and above, and join the nforce2 fsb 200 club (lol).

Dual channel (dimm1+dimm3) will buy you little or nothing on memory BW at this point, but running at a few MHz higher (above 200 MHz) will greatly improve memory BW and 3D performance.

dual channel has an awsome positive affect on 3dmark scores, running single I loose over 1,500 points. I would never run single if I could run dual

nikhsub1 said:

This seems to be very normal.... Best OC with any board is usually with 1 stick. Enabling dual channel on NF2 boards seems to yeild the lowest FSB OC. I like to run DC so I will take a few Mhz lower than single channel.

Click to expand...

It seems you concur that running dual channel (dimm1+dimm3) locks off a few MHz on the FSB than the single channel (dimm1+dimm2). Then what is the advantage of running it in dual channel rather than single channel with two sticks in dimm1+dimm2?

Am I missing something?

Accurate said:

dual channel has an awsome positive affect on 3dmark scores, running single I loose over 1,500 points. I would never run single if I could run dual

Click to expand...

I am talking about A7N8X-dlx, nforce2 chipset here.

Have you tried pushing the max stable FSB when the two sticks are in dimm1+dimm2 (single channel mode), and in dimm1+dimm3 (dual channel mode) respectively? Do you see a difference in the max stable FSB between the two?

For me, every other things being the same, I can get 5-7 MHz higher on the FSB when the two sticks are in dimm1+dimm2 than in dimm1+dimm3. And such few MHz on FSB translates into higher overall memory bandwidth and 3D mark benchmarks.

Am I missing something here?

Normal - overclocking in dual mode is much more difficult than single mode, and larger modules are typically harder to drive as fast.