Archived from groups: alt.comp.periphs.mainboard.asus (
More info?)
Thanks for the detailed explanation.
The reason I dont want 4 dimms is because, as you stated, you have to run
your memory at reduced settings.
I would rather run 3 dimms at full settings. But, the ideal solution is
always the costliest. Sell my ram, and get 2x1GB dimms.
"Paul" <nospam@needed.com> wrote in message
news:nospam-2904052000380001@192.168.1.178...
> In article <vdyce.428$fF6.6440@news1.mts.net>, "edde"
> <waver777@hotmail.comNOSPAM> wrote:
>
>> I currently have been running an A8N-SLI Deluxe system for months now
>> with
>> no problems.
>> I currently have 2x512MB OCZ PC3200 EL Dual Channel memory.
>>
>> I do alot of image editing, and now with Photoshop CS2, 1GB is just not
>> cutting it. The expensive solution would be to sell my dimms, and buy
>> 2x1GB
>> PC3200 EL Dual Channel memory.
>>
>> However, could I just buy 1 more dimm of 512MB or 1GB memory and put it
>> in
>> the third slot? I know that running 4 dimms can sometimes cause problems,
>> or
>> force you to use slower timings, but would running 3 dimms as above be
>> problematic at all?
>
> S939 is not really dual channel. In AMD parlance, the system
> operates in 64 bit memory mode, or 128 bit memory mode. Think
> of it as a narrow single channel, or a wide single channel.
>
> See page 14 of this doc:
>
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/31411.pdf
>
>
> When in 128 bit mode, the only valid configurations are
> two DIMMs or four DIMMs. The channel width must be maintained,
> and once you decide to go "wide channel", the DIMMs have to
> be installed as functional pairs.
>
> Three DIMMs would mean that the third DIMM would be missing
> its partner. The processor would attempt a 128 bit access, and
> 64 bits of that would be driven by "air".
>
> Why not just buy 2x512MB DIMMs _exactly_ like the ones you've got.
> You can run them DDR333 command rate 1T or DDR400 command rate
> 2T (this assumes a CG stepping or later processor, as I seem to
> remember some mention of the command rate option only being
> implemented on later processors). And by the way, I'm not
> kidding about the "exactly" part - there have been what
> appear to be BIOS problems, with using two pairs of DIMMs that
> don't have the same SPD contents on the DIMMs:
>
>
http://groups.google.ca/groups?threadm=nospam-1404050820080001%40192.168.1.178
>
> The DDR400 2T setting will give slightly more performance than
> DDR333 1T. At least one poster here reported that as the
> result of his testing.
>
> Selling your DIMMs and buying 2x1GB is certainly an option, as
> then you might be able to get more performance from the RAM. It
> all depends on how much more money you have to splash around, for
> that little bit of extra memory bandwidth.
>
> HTH,
> Paul