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View Full Version : Mixing single & double sided DIMMs?


Justin Baker
March 16th 06, 09:34 PM
I'm looking to buy a socket 939 board and I want to use my existing RAM if
at all possible - I have four Crucial 512Mb DDR400 DIMMs, two of which are
single sided and the other two are double sided. If I put the single sided
DIMMs on one channel and the double sided DIMMs on the other channel, is
this likely to work?

Thanks,

JB

General Schvantzkoph
March 17th 06, 03:07 AM
On Thu, 16 Mar 2006 20:34:40 +0000, Justin Baker wrote:

> I'm looking to buy a socket 939 board and I want to use my existing RAM if
> at all possible - I have four Crucial 512Mb DDR400 DIMMs, two of which are
> single sided and the other two are double sided. If I put the single
> sided DIMMs on one channel and the double sided DIMMs on the other
> channel, is this likely to work?
>
> Thanks,
>
> JB

As long as you pair the single with the single and the double with the
double it will work fine.

Justin Baker
March 18th 06, 12:38 PM
"General Schvantzkoph" > wrote in message
...
>
> As long as you pair the single with the single and the double with the
> double it will work fine.
>

Thanks for the reply, I was hoping that would be the answer!

Next question, will I be able to run the memory at DDR400 in this
configuration, or will it fall back to DDR333?

Thanks,

JB

General Schvantzkoph
March 18th 06, 02:34 PM
On Sat, 18 Mar 2006 11:38:14 +0000, Justin Baker wrote:

> "General Schvantzkoph" > wrote in message
> ...
>>
>> As long as you pair the single with the single and the double with the
>> double it will work fine.
>>
>>
> Thanks for the reply, I was hoping that would be the answer!
>
> Next question, will I be able to run the memory at DDR400 in this
> configuration, or will it fall back to DDR333?
>
> Thanks,
>
> JB

A single sided plus a double sided on each bus will run at DDR400. The
speced speed for a system with four double sided DIMMs is 166MHz (DDR333),
for a system with two double sided and two single sided the speced speed
is 200MHz (DDR400). However if you use faster memory and up the DIMM
voltage slightly a system with four double sided DIMMs can run at DDR400
reliably. I have 4G in my X2 4400+ system. Initially I had two pairs of
OCZ value RAM. With that configuration I was only able to run at 166MHz. I
replaced one pair with OCZ performance RAM and upped the DIMM voltage
slightly and I've been running at 200MHz for months without a single
hiccup.