memory - Is there a way to programmatically/universally determine the maximum RAM speed a computer supports?

08
2014-07
  • Zac B

    Say I have a computer, standard 32 or 64-bit architecture. I can put any OS on it (*nix, Windows, etc). Is there some way for the computer to interrogate the hardware as to what the maximum RAM speed supported is, that works universally?

    By "universally", I mean that this solution should work even on devices which aren't known to it/in its internal dictionary of parts/chipsets/processors/whatever. Right now, I can run dmidecode on a random MB and 9/10 times it will give me the correct current system specs. But that doesn't tell me the max supported RAM speed, and it is also wrong more than I'd like: especially on newer motherboards running older OSes, and in strange UEFI/BIOS compatibility environments.

    Is this possible? If not, why not?

    • Answers
  • David Schwartz

    I would say it's easy to show it's impossible.

    On a modern system, the memory controller is on the CPU. The maximum supported memory frequency is the lower of what the CPU supports and what the motherboard supports. Without a CPU database, the only way to tell the maximum frequency the CPU supports is for the BIOS to tell you. While BIOSes are supposed to report the actual clock frequency in the DMI table, there's no standard entry for the maximum supported frequency.

    Another problem is that the DMI table has the actual clock frequency. If you are looking for the effective frequency (which is how RAM speed is usually reported), that would also require the program to understand the RAM technology's effective-to-actual ratio. What if QDR RAM becomes popular? Can you write a program today that can accurately detect QDR SDRAM that doesn't even exist as a specification yet?


    • Related Question

    memory - Ram capacity of my computer
  • Questioner

    2 years ago I bought a Dell Dimension 9200 desktop computer as a high end gaming computer (at least, back then it was a top of the line computer). The computer was ordered with 4GB of RAM, but came in 4 1GB sticks.

    2 years later I am actually finding that my computer does not have enough RAM (I have some analysis programs that will chew up any bit of RAM/CPU power you throw at them) thus I need to upgrade.

    Here's the problem:

    After a bit of digging around to find out what type of RAM my computer supports, i found out that my computer is supposedly already maxed out in terms of RAM. I have 4 RAM slots and the manufacturer (Dell) says that the system can only accept 1GB RAM sticks. All other sources on the internet also say that my desktop is only capable of handling 1GB RAM sticks.

    However, I ran Lavalys' EVEREST program and it says my computer is capable of handling up to 2GB RAM sticks, for a maximum of 8GB total.

    I have confirmed that my computer does indeed handle 2GB sticks. Unfortunately I only had 1 stick on hand and was only able to test the computer in single channel mode.

    My question is, is my computer actually capable of handling the full 8GB of RAM despite what the manufacturer, and pretty much everyone else says? Should I go ahead and spend that $100 on the RAM?

    A side question, I hear about RAM requiring about 15W of power per 1GB, should i be worried about my system not having enough power if i upgrade? I run a Q6600 (TPD 140W), 1 hard drive, an 8800GTX (peak 290W) and 1 DVD burner. Nvidia recommends at least a 500W power supply when running an 8800GTX, but Dell cheaped out on me with a 450W, will the extra 4GB of ram (possibly adding an extra 60W of load) cause me any problems?

    Thanks in advance,

    -Faken


    • Related Answers
  • John T

    Have you tried Crucial's scanner? I'm sure it will give you a more definitive answer. Alternatively, try booting with only the 2GB stick, and run memtest to check stability. Most linux distributions with a LiveCD come with memtest on the disc as well.

  • nik

    I recently referred the Crucial tool CrucialScan.exe at
    Can a 800Mhz memory stick be used in a 400Mhz slot?.

    It would be a good trick for your system too.

  • Dan Walker

    To answer your other question, your power supply should be fine. I'm running a similar config with a 8GB of memory and a 400W power supply with no issues.