I find myself looking for RAM speed and size quite often at my current workplace. A useful tool included in some flavours of linux is the dmidecode command which will dump a computers DMI table (SMBIOS) to human-readable format. I also gives a ton of other useful information about the BIOS and hardware.
sudo dmidecode --type 17
Also, take a look at this resource site for more information about this BIOS decoding utility and a reference table for what "type" = what hardware or information: http://www.cyberciti.biz/tips/querying-dumping-bios-from-linux-command-prompt.html