Dual Channel won't work

HarudathHarudath Great Britain Icrontian
edited November 2009 in Hardware
Hey guys, tis me again

Basically my RAM won't overclock while in dual channel mode, and it's supposed to. The RAM modules I have are Kingston HyperX 2GB PC2 8500 CL5 240 pin DiMM Kit (2 pcs) or KHX8500D2k2/2GN. Its stock is 800MHz but was sold with the promise of 1066MHz overclockability. The RAM doesnt seem to be dodgy; CPU-Z is showing the norms as far as I can tell and is reading both modules with no problem.

When the RAM is run in single channel I can reach 1066 no problem apparently single channel aint no gud fer bandwidth. The board I've got is a DFI LanParty P45-T2RS Plus and clearly states on the box it supports 1066MHz and up to 1200Mhz OC'd. When I try to overclock in dual channel mode, above about 900Mhz (Not too stable, but usable) I get crashes at/before the POST or when I try to do anything on bootup.

Let me know what more information you need and I'll be happy to supply.

Thanks again Icrontic! :rockon:

Comments

  • RyderRyder Kalamazoo, Mi Icrontian
    edited December 2008
    What settings are you using when you overclock?

    What FSB, what ram divider are you starting with?
  • ThraxThrax 🐌 Austin, TX Icrontian
    edited December 2008
    And what voltage?
  • HarudathHarudath Great Britain Icrontian
    edited December 2008
    Core speed 3400Mhz
    Multiplier x 8.0
    Bus speed 425 Mhz
    Rated FSB 1700MHz

    DRAM Frequency 510Mhz
    FSB:DRAM 5:6
    CL : 5.0 clocks
    tRCD: 5 clocks
    tRP: 5 clocks
    rRAS 18 clocks

    CR: 2T

    I think that's what you meant- I'm still learning overclocking
  • HarudathHarudath Great Britain Icrontian
    edited December 2008
    //EDIT: Voltage is 2.0V
  • RyderRyder Kalamazoo, Mi Icrontian
    edited December 2008
    So you are at 1020 for ram speed with 425 FSB.. what are you complaining about?

    No.. that voltage is not what is set in the bios.. what do you have set there?
  • HarudathHarudath Great Britain Icrontian
    edited December 2008
    Bios says 2.0V, I was just quoting CPU Z before, sorry.

    The problem is that I cant do that in dual channel mode and as far as I'm aware I'm meant to be able to: currently Im in single channel and if overclock at all I have system instability. When I last checked memtest threw up errors when the RAM was in dual channel mode, but not single channel.
  • RyderRyder Kalamazoo, Mi Icrontian
    edited December 2008
    Ok.. what slots are you in?

    Is this the DK P45 or regular?

    Set the FSB to 333, set the ram to 1066.
  • HarudathHarudath Great Britain Icrontian
    edited December 2008
    It's the P45 PLUS, and doesn't that decrease the overclock on my CPU?
  • RyderRyder Kalamazoo, Mi Icrontian
    edited December 2008
    Yes.. but you need to find out if the ram will run 1066, which is what you want right?

    Put them in Dual Channel and run stock FSB with ram set to 1066. If it runs.. then it is something else causing the issues.
  • HarudathHarudath Great Britain Icrontian
    edited December 2008
    Aha, gotcha. Will post results soon
  • HarudathHarudath Great Britain Icrontian
    edited October 2009
    Ok, so its sorta only a year late... I kinda gave up before and resigned myself to single channel but I want to get this sorted now, finally.

    Right.

    Tried FSB stock and setting the RAM to 1066 in dual channel; that didnt work. Dual channel doesnt work at all, even at stock with my normal RAM, its just irritatingly unstable. I can overclock decently in single channel, though (1021, perhaps higher).

    Dad brought some home spare RAM from work to try and troubleshoot. It runs dual channel no problem up to 1021, after that I get crashes/instability at or during startup. 1065 is the closest I can get to 1066 and its unstable.

    Both sets of sticks use the same voltage and timings as stated on Kingston's site. Any ideas?

    Original RAM
    KHX8500D2/1GN
    5-5-5-15
    2.2v

    Test RAM
    KHX8500D2K4/4G
    5-5-5-15
    2.2v

    FSB is currently 425, multiplier 8.

    Dunno what other info is needed, just ask if its lacking ^^

    Thanks Icrontic, I gotta remember to check back here more often X_X
  • lordbeanlordbean Ontario, Canada
    edited November 2009
    I think I've seen something similar to this problem before with a couple of OCZ modules on an Asus board... They needed a special tweak done in the BIOS to get over 800MHz, even though they were supposed to run 1000MHz...

    See if you can find any Clock Skew options for your RAM. Specifically, you're looking to see if you can control the Clock Skew for Channel 2 (or possibly Channel B) only. If you have such an option, set the ram to 1066, and gradually increase Channel B's clock skew. You may hit a point where it works.
  • HarudathHarudath Great Britain Icrontian
    edited November 2009
    I couldn't find anything, other than a CPU clock skew, though I'm not sure what effect that would have (except for altering the individual cores? I don't know) on the system. Never used it before.
  • lordbeanlordbean Ontario, Canada
    edited November 2009
    That setting unfortunately wouldn't help here... if it was there, it would definitely reference the RAM channels, not the CPU. What a clock skew does, as I understand it, is to introduce a very slight lag into the system's access of the RAM installed in either channel. Due to the different designs of motherboard PCB connection paths, this is sometimes necessary to bring high-speed RAM into synchronization. That's why my DDR2-1000 modules wouldn't work on my old Asus board without having the tweak done.

    I have no idea whether this is actually the problem in your case or not, but it sounds likely from the symptoms.
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