a7m266-d memory conf

KL wrote:
>
> I have a working a7m266-d computer with one 1GB registered ecc memory
> module.
>
> Is it possible to add normal unbuffered ddr memory with that existing
> ecc/reg module? I have two unbuffered PC3200 512MB modules, is it safe
> to test those at the same time with the reg/ecc chip?

The manual says four registered sticks OR two unbuffered sticks.
There is no mention of mixing them. I'm not aware of any
motherboard that allows you to mix them on the same bus.

http://www.upgradememory.com/A7M266-D_C8038.cfm

"System Notes: Registered and Non Registered Memory cannot be mixed."

If you were to mix them, a well designed BIOS will read the
SPD on each DIMM, and figure out that more than one type is
present. You should get a beep error code in that case, and
no POST.

http://www.firingsquad.com/hardware/760mpxroundup/page6.asp

"To test unbuffered memory support we chose to use three types of memory
modules from Corsair, Crucial and Mushkin. Asus states that only the
first 2 DIMM sockets support unbuffered memory but our tests indicate
otherwise. We installed three different unbuffered modules into 3 sockets
and to our surprise the board worked."

While that is an interesting observation, I wouldn't rely on
it if purchasing new modules at this point in time. One
other observation, is the manual didn't even bother to
state which two slots you are supposed to use, if using
unbuffered memory. According to the AMD documentation,
there are a limited number of clock signals available,
and I don't want to think about how Asus abused them,
to support both kinds of RAM

Best guess,
Paul