5 Replies Latest reply on Nov 10, 2009 3:46 AM by Ziggy

    Indicated Memory Speed DX58SO?


      In September I built a machine with a DX58SO MB and a Core i7 920 processor.  I used COSAIR XMS3 6GB (3 x 2GB) DDR3 1600 memory.

      When I go on the BIOS "MAIN" Menu, it shows "Memory Speed 1067 Mhz".

      Could someone please explain why this is, and if it is correct?  (The only thing I can guess is that to get the faster speed you need a faster i7 than the i7 920?)

      Thanks for your insights!


        • 1. Re: Indicated Memory Speed DX58SO?

          BIOS layout is not that easy but here goes.


          BIOS > Performance tab > Memory Overrides > Performance Memory Profiles > if XMP is listed use that if not use Manual >


          Memory Multiplier > 12

          tCL > 9

          tRCD > 9

          tRP > 9

          tRASmin > 24

          tRFC > 88

          Memory Voltage > 1.65

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          • 2. Re: Indicated Memory Speed DX58SO?

            Hate to tell you this, but the i7 920 cannot use memory faster than 1066. Moreover, it cannot drive memory with a voltage over 1.6, which is what it takes to run that memory. Oh, and if you have any problem with your processor or board after attempting to run faster memory, Intel will tell you to take a leap because you voided the warranty. The board is capable of doing this, but the CPU is not. And, as I found out, even if you run memory at the right speed and voltage, they will not help you, should you have a problem, if the memory is not on the compatibility list published on the Intel website.

            • 3. Re: Indicated Memory Speed DX58SO?

              Dear hmf,

              What you say makes perfect sense to me- after I thought about what I saw looking in the BIOS performance parms for the CPU.  These seemed to indicate that the cpu is running at 1067 clock rate (?), and since the i7 directly accesses the memory (or so I understood from their architecture block diagram), that's as fast as the 920 wants to go in memory speed.

              Anyhow, I was more curious than anything else, thinking initially that the BIOS needed to be updated, or something; but it remained the same after I installed the latest BIOS.

              I have more than enough compute power for my purposes, and so far love the machine I built!

              THANK YOU very much for your answer.


              PS I posted a separate question about "gracefully" getting out of my current RAID 1 array (which has VISA installed on it) to a NOT-RAID configuration.

              Would you, perhaps, have insight into this?  Thanks again!

              • 4. Re: Indicated Memory Speed DX58SO?

                actually thats wrong, hmf. speeds above 1066 are supported, only the memory controller of the specific cpu doesn't run faster than 1066 without overclocking. speaking of oc, the ram you bought is intended for exactly that - overclocking. it is, of course, capable of running at 1333 with the standard voltage for ddr3.

                better go with "standard" ram next time. saves you money and avoids the confusion.

                • 5. Re: Indicated Memory Speed DX58SO?

                  Most Corsair RAM defaults to 1066 MHz and has to be manually configured. I originally had their basic 1333 MHz RAM installed and yet they even have this boot at 1066 MHz. Manually setting the timings was the only solution, and I eventually ended up using two of the three modules in a Core 2 build I was putting together for someone. I bought some inexpensive Crucial 1066 MHz as replacement which runs at the correct timings without any messing around. I haven't noticed any performance loss whatsoever. Synthetic benchmarks will show a significant increase in performance with RAM of a higher clock speed but in real world terms the difference is typically a few percent at best. From past experience the best O.C. results have come from tweaking latency rather than clock speed anyway but I'm not willing to cook the i7's on-die memory controller for such a small and probably negligible performance gain. For now I'm content to enjoy the benefits of triple channel and hyper threading. Oh, and it's not specific to the 920. Even the 975 has the memory controller rated at 1066 MHz.