SDRAM or DDRAM in linux

[Niklaus]

Hi,

 I have access to a remote linux machine. I have a root account on it.
 I need to know whether the installed RAM is SDRAM or DDRAM.
Unfortunately i will be going to the site next month when i have to
upgrade the machine with  more capacity. Few of them are hardware
related but if you know the answer please help me.

1) How do i find out when the machine is online , if it is SDRAM or
DDRAM. I tried dmidecode utility but i was not sure about the type.
Can someone help me out by pasting the output for both DDR and SDRAM
in dmidecode or similar.

2) Can both SDRAM and DDRAM be present at a time in the same
motherboard. I mean can i have 256MB of SDRAM chip and a 256 MB of
DDRAM on the same motherboard.

If yes what are the conditions.


3) Is a motherboard designed for only one type of RAM , like if we
remove all the SDRAMs can we put DDR in it or it is either designed
for DDR or SDRAM.

Regards
Nik