4x DIMM (DDR2) stability?

[Flogger23m]

I have 4GB of spare Corsair XMS2 DDR2 CM2X2048-6400C5 sitting around. It is a set of two DIMMs.

I currently have the exact same set in my PC (accept for the version number on the stickers, one set is V3.2, the other V3.4). I am thinking of adding the extra two DIMM/4GB of RAM into my PC, but I am wondering if it will be stable? I've read in that past that some motherboards have stability issues with more than two DIMMs, so I would like to know if this is something to be concerned about. I do not OC and have no plans to, so that is not an issue. In the end, I will have 8GB in 4 DIMMs.

Assuming it is stable and works fine, will my RAM still be working in duel channel?

My specs:
ASUS M3N78 Pro with latest BIOS
AMD 965
Win 7 Pro 64bit
GTX 260
Antec 500 Earthwatts

 

[LiveOrDie]

yes and should work fine.

 

[crazyeyesreaper]

it should work fine if not you might up to up the CPU- NB voltages or the DIMM voltage by a notch

usually its 1066 4 dimms you need to run 800 for stability this is do to stock CPU-NB volts upping those volts should allow all for 4 Dimms to be populated and run proper timings

and 800mhz 4 dimms acts the same its recommend by amd to drop the ram speed by 1 multi if 4 sticks are in the machine

1066 x 4 dimms drop to 800mhz

800mhz x 4 dimms down to 667,

again you can still run the rams rated speeds with a small voltage bump to the CPU-NB

 

[timta2]

If you run Memtest and it passes you should be ok. I always test the memory when I'm fooling around with it or adding something new. It looks like you have a quality motherboard so I don't think you should worry.

 

[Flogger23m]

it should work fine if not you might up to up the CPU- NB voltages or the DIMM voltage by a notch

usually its 1066 4 dimms you need to run 800 for stability this is do to stock CPU-NB volts upping those volts should allow all for 4 Dimms to be populated and run proper timings

and 800mhz 4 dimms acts the same its recommend by amd to drop the ram speed by 1 multi if 4 sticks are in the machine

1066 x 4 dimms drop to 800mhz

800mhz x 4 dimms down to 667,

again you can still run the rams rated speeds with a small voltage bump to the CPU-NB

So will I have to set my DIMMs from 800MHZ to 667MHZ manually in the BIOS? Or will it be done automatically?

And will this show a decrease in performance for the programs I run that use less than 4GB of RAM?

 

[crazyeyesreaper]

you would have to do it manually

but again just bumping the CPU-NB up 1 notch in volts will stabilize the ram,

aka say 1.1v is the CPU-NB default *i cant remember if it is its just an example*

setting it to 1.2v would stabilize the ram at its default speeds. without any harm to the cpu etc.

 

[Flogger23m]

Ok, thanks for the advice. I will give this a try shortly. If anyone has any input feel free to give it.

 

[Bo$$]

Increase the NB 1 notch, this should be more than enough, set the timings manually and bang you have 8gb

 

[JrRacinFan]

Just expanding upon your post Bo$$/crazy; PhII NB aka IMC(integrated memory controller) as what he is referring to. Most PhII IMC's default to ~1.2v say bumping that to about 1.25-1.3v(dependent on your CPU's binning and CPU-NB VID) should stabilize them pretty well.

 

[Flogger23m]

So far I put in the RAM. I've played BF3 beta and Crysis Wars as well as left my PC on for hours non-stop. So far no stability issues to report. According to CPU-Z the timings for all DIMMs are the same (what they were before I put in the extra 2).

Later today I'll load up a bunch of programs at once to see if there is any stability issues when using large amounts of RAM. If I get stability issues I will try increasing the NB a notch.

Thanks for the help everyone.

 

[Bo$$]

well thats nice, good luck mate!