Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I am using two modules of RAM and I would like to know their frequency because at simple sight, I can't see any sign of it in the modules.

When I ran memtest one time, it showed me the test settings' values (some related to the RAM), but on subsequent runs it showed me another set of values; values which I don't understand because I haven't find a fair reasonable user guide. Furthermore, I cannot control the settings of memtest. The program, launched from grub's menu, does not respond to keystrokes in a Macbook Pro with dual boot (Mac OS and Natty-amd64-mac).

I would also like to know if the impossibility to control the program with the keyboard is normal in Mac computers? or I did something wrong during the installation?. Can I fix that?. Is it still like that in newer versions of Ubuntu?

Also: Is there a way to change the frequency of the RAM, like in the bios, in refit's shell or grub?

share|improve this question
You can download a program such as AIDA64 it is a Windows software though, but works fine on Wine. Memtest is for testing RAM. – Uri Herrera Nov 13 '12 at 5:44
"Also: Is there a way to change the frequency of the RAM, like in the bios, in refit's shell or grub?"- Easiest way it's doing it from your BIOS, if yours support it, if not then I'm not sure if it can be done via software in Linux. – Uri Herrera Nov 13 '12 at 5:50
Thank you. But that program, AIDA64, what for? What question will it answer?. Does it run on Mac before booting? – Robert Vila Nov 16 '12 at 16:56
You could try to plug in a USB keyboard and see if memtest reacts to that. – taneli Nov 16 '12 at 20:04

See if your computer supports DMI, which usually has information about memory components (including speed):

sudo dmidecode -t memory
share|improve this answer
Thank you. That displays Speed: 667 MHz (1.5 ns). But what is that value talking about exactly?. What confuses me is that, AFAIK, a memory chip can work at different frequencies; Bios can change that. But in this Mac I don't know if it can be changed and how to check the frequency at which it is being used. I am asking this because the different values in different memtest runs made me think that something might be wrong or not properly configured – Robert Vila Nov 16 '12 at 17:12
My understanding is that BIOS fills in the DMI information. I suppose an indication of "Speed" is the maximum, as there is a separate value called "Current Speed" (some computers I checked have the latter, others the former, none both). I wouldn't be terribly surprised if some BIOS presented incorrect values (or attribute names). – taneli Nov 16 '12 at 20:04

I ran dmidecode -t memory with my 2400 MHz ram clocked at 1866 MHz in the BIOS:

Handle 0x0042, DMI type 17, 34 bytes
Memory Device
        Array Handle: 0x003F
        Error Information Handle: Not Provided
        Total Width: 64 bits
        Data Width: 64 bits
        Size: 4096 MB
        Form Factor: DIMM
        Set: None
        Locator: ChannelA-DIMM1
        Bank Locator: BANK 1
        Type: DDR3
        Type Detail: Synchronous
        Speed: 1867 MHz
        Manufacturer: 04CB
        Serial Number: 00000414
        Asset Tag: 9876543210
        Part Number: DDR3 2400 2OZ     
        Rank: 1
        Configured Clock Speed: 1867 MHz

So apparently it's the configured speed.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.