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DDR DRAM FAQs And Troubleshooting Guide

How Do I Overclock DRAM?

Overclocking DRAM is no different from doing so on a CPU or GPU. This is the approach I’ve found to be easiest for most people:

  1. Ensure you have the latest BIOS.
  2. Go to BIOS, and raise the data rate one level. If DRAM is at 1600 MT/s, bump it up to 1866. If it’s 1866, try 2133, etc.
  3. Raise the timings by 1-1-1-3. If the DRAM is 8-8-8-24, try 9-9-9-27. If the DRAM is 9-9-9-24, try 10-10-10-27.
  4. Raise the DRAM voltage and MC voltage +50mV (0.050V) each.
  5. Reboot, and if the boot succeeds, test for stability. Windows has a built-in memory stability tester, and many of our own overclockers use the mixed-mode “torture test” of Prime95.

If you have problems with the steps listed above, try increasing the MC voltage by another + 50mV (0.050V). Note: AMD CPUs might need even more MC voltage (normally the CPU/NB). Still not having success? Try overclocking the CPU slightly, if it can be overclocked. If not, try a slight increase in CPU voltage—about the same you tried with the DRAM and MC voltages (+0.050V).

(Editor's Note: The 1.65V DRAM limit for Intel CPUs isn't completely without merit. Many experienced overclockers have found that reducing the difference between the CPU MC and DRAM signal voltage can prolong the life of their overclocked processors, and have approached this theoretical limit from the other direction by increasing the memory controller voltage and DRAM voltage simultaneously. Recent testing of DDR4 memory controllers has also revealed several CPU samples that become less stable with memory pushed beyond 1.37V, where DDR4 starts off at 1.20V rather than 1.50V. The two points can that can be gleaned from this experience are that adding 50mV to 1.65V DDR3 or 1.35V DDR4 will likely not improve stability, and that doing so may shorten the life of the CPU. Because there are so many variables to play with, we recommend beginning overclockers consult several forum experts before exceeding 1.65V DDR3 or 1.35V DDR4 on Intel's current and previous two processor generations. Jim's advice remains valuable for these processors when applied to 1.50V DDR3 and 1.20V DDR4.)

These are rather simple approaches; if they don’t work, you can try contacting the manufacturer. However, you may not get the results you're looking for, as many manufacturers don't like it when you overclock their DRAM. Therefore, I also would suggest looking for help in the forums.


MORE: Best Memory
MORE: Memory in the Forums

Jim Reece is a Contributing Editor for Tom's Hardware, covering Memory.

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  • Nuckles_56
    Thank you for this useful and informative article
    Reply
  • das_stig
    With AMD motherboards, you should set the memory to unganged mode for a tiny performance improvement unless you're running a webserver.
    Reply
  • vicstead
    Thank you Jim for this very informative article, an enjoyable read.
    Reply
  • Mahruay
    Nice read although could you explain what real world improvements can be seen in faster RAM.
    Reply
  • boju
    Nice article, answers a lot for people and definitely will link for future references. I need to ask though, is there any reason to discriminate DDR3 as per title?
    Reply
  • TechyInAZ
    Wow this is very informative thank you for this!!
    Reply
  • MPA2000
    Lost me after Virtual v Physical.
    Reply
  • clonazepam
    I hope the next part covers performance when using say 3 sticks, where 2 are dual channel, 1 is single channel. Some real world results would be stellar (maybe as a follow-up?)

    I'd also like to see RAM drives covered. Suppose you allocate 4GB out of 16 for a RAM drive. How does the software create the 4GB? Is it using a single chunk of memory, is it taking 1GB from each of the 4 sticks? Is it from the beginning, middle or end of the 16GB of memory?

    Covering how to identify true "memory leaks" versus a more common scenario where RAM usage grows intentionally from the caching of more and more assets.
    Reply
  • damric
    Great article, Tradesman! I give it Two thumbs up and two big toes up too!

    Only 1 issue:

    Ganged vs Unganged: that actually doesn't have to do with single or dual channel.

    Quote AMD:
    Ganged mode means that there is a single 128bit wide dual-channel DRAM Controller (DCT)
    enabled. Unganged mode enables two 64bit wide DRAM Controllers (DCT0 and DCT1).
    The recommended setting in most cases is the Unganged memory mode. Ganged mode may allow slightly
    higher Memory performance tuning and performs well in single-threaded benchmarks.
    Depending on the motherboard and BIOS, it may be required manually setting the timing parameters for each
    DCT (in Unganged mode) when performance tuning the memory or fine tuning the timings. Some BIOS
    versions apply the same timings automatically for both DCTs in an Unganged mode.

    Unganged is like a normal divided highway with two directions. Ganged let's traffic use all of the lanes in one direction at a time. Unganged is said to be more efficient but no one really ever tested this thoroughly to see if any applications would be better served in ganged instead. You could still have unganged single channel or dual channel, and ganged single channel or dual channel. If that's confusing I'll try to explain with more complicated interstate highway anecdote.

    Lastly, I see you have a new AMD rig. Did your head explode when you saw how much more difficult it is to tune memory on that platform than on your past intel rigs?


    Reply
  • Shankovich
    Awesome article! These kinds of articles is what brought me to Tom's in the first place years ago!
    Reply