New Athlon II 245 only runs DDR2 with 1 DIMM per channel

I've searched high and low for an answer to my problem.

This has been a staggered computer upgrade. I got an asus M4A78-EM a few months ago to replace a dead AM2 board. It's an AM2+ board (although it was branded as "AM3 ready" but I digress).

With my old Athlon x2 4000+ this board (and my old board) ran my Mushkin 2x1GB DDR2 667mhz RAM fine in dual channel (slots 1&2). When I got my new Athlon II 245 last week, it wouldnt POST. I pulled one stick of ram out and it ran fine. I now have my RAM in single channel, in slots 1 & 3.

Ive posted on asus' and AMD's websites and no replies. I tried a pair of 1gb DDR2 533's and got the same result. I tried my RAM in slots 3&4, no POST. I have the latest bios for the MB so thats not an issue.

I have the CPU running GREAT, OC'd from 2.9 to 3.4, and going no more than 40°c with the puny little stock cooler and stock voltage! But I'd love to be back in dual channel.

According to ASUS, this board only supports 1 DIMM per channel for DDR2 1066, but 2 DIMMs/channel for 800 or less. According to AMD, Athlon II's only support up to 800mhz for DDR2 anyways. I plan on getting a 2x2GB kit in the near future but if this machine is stuck in single channel, I may just get a mismatched 2gb DIMM and get it over with.

Any suggestions? Any answers as to why? If there's a reason, and I'm SOL, I can move on. But if there's a way out of this, thats even better!

Please let me know if any other info will help
12 answers Last reply
More about athlon runs ddr2 dimm channel
  1. Underclock your RAM.
  2. check the official AMD specs as to what that processors IMC can actually do, and what it cannot do for that matter, other then that i believe amdfangirl is right and this is common - even the older 939 amd's were "officially" limited to lower speeds when 4 ram sticks were used regardless of supporting DDR400 etc
  3. Quote:
    dual channel should be slots 1 and 3 or slots 2 and 4. If your trying int 1 and 2 or 3 and 4, thats not dual channel. Read manual.

    Are you dimm voltages set right in the bios?

    also a verry good point and mistake i see all too often - Intel and AMD memory out's are totally different unless the motherboard is from MSI (idiots), or ASUS with the P6T (i7 based system) where the 1st slot of every channel is actually the 2nd) - manuals people
  4. Quote:
    dual channel should be slots 1 and 3 or slots 2 and 4. If your trying int 1 and 2 or 3 and 4, thats not dual channel. Read manual.

    Are you dimm voltages set right in the bios?

    Let me reiterate: I had the ram in slots 1&2 running in dual channel with my old AM2 chip. With them in 1&3, cpuz reads them as being in single channel. Besides, even if i had things backwards it should still POST in slots 1&2 with this chip...

    In fact my manual does say 1&3/2&4. Other sources (asus) have long ago confirmed that the manual was miprinted. When I 1st got this MB I followed the manual, put my DIMMS in 1&3 and it was in single channel. Put them in 1&2, or 3&4 and read as dual. I tend to trust what POST messages and cpuz tell me in the running machine.

    And I dont even want to think about what would happen if i tried to populate all 4 slots with an issue like this

    @amdfangirl: underclocked attempted, no joy
  5. Loosen Ram timings, increase Ram voltage. Run memtest with each stick of ram to make sure both sticks are ok.
    Have You tried slots 2 and/or 4 on their own? Could be bad memory controller in new cpu
  6. Bad memory controller my a$$ - read the AMD specs on that cpu/imc
  7. apache_lives said:
    Bad memory controller my a$$ - read the AMD specs on that cpu/imc

    So from what Ive read athlon ii cpu's support up to ddr2 800/ddr3 1066 in dual channel. mine is 667... you want to enlighten me as to what youve read that differs? If you know something, dont hold out on me! Or just the same, can someone who knows how to share answer for him? :kaola:
  8. Well, I'm stumped. I think that you'd be best to RMA that CPU and try it again. Parts are easy to screw up on the manufacturing level, with their millions and millions of transistors and such, so things happen, and that's why warranties are awesome. :)
  9. Quote:
    i build hundreds of PC's a month and service thousands - its rare to get a dud cpu unless you didnt handle it correctly etc - people RMA things they blame when there fine, and if you sir actually read your manual correctly you would read this:

    Due to AMD CPU limitation, DDR2 1066 is supported by AM2+/AM3 CPU for one DIMM per channel only.

    took me under a minute to find it


    Ok, so are you (and asus) TRYING to say 1066 OR LESS is supported for only 1DIMM/channel? I understood this to mean only DDR2 1066 has this limitation. Not 800, 667 etc.

    I posted on here to find a solution that didnt involve RMAing anything. Other ppl are suggesting that on a whim. Whether that meant some tweak, buying different ram, or finding someone with a reason that its impossible with this mb/cpu. If that is the case, than so be it, I just needed answers to an outstanding question.
  10. Roldy, I know that problem, and it is not a problem of the CPU or Motherboard, but a memory one. It happens in all CPUs that have integrated memory controller (Athlon64/phenom/corei7) when used with memories that work at their limits.

    Those memories may had worked on your old Athlon 64, but your new Athlon II is faster, and uses memory faster (stresses them more). So they don't work now in dual channel. Timings and memory speed is not everything.

    I have seen this happen on people that had DDR3 memories with intel Quads and moving them to i7 systems, so this is not an AMD only problem.

    Your options? Underclock them as much as you can, but because this is a workaround, I would suggest to buy some high performance branded memories.
  11. Quote:
    Well lets make it simpler, if you put your two dimms in two different slots that are the same color, your in dual channel. If they are in different colors, thats single channel mode.

    Indeed, I had them in the 2 yellow slots with my AM2. But other ppl are right, the manual does say the 1st yellow and 1st black are channel 1. Like Ive said, this has been confirmed as a misprint.

    @GNR: I can appreciate that, Ive tried underclocking to no avail (@ stock cpu speed of course, dont want to fudge my results having my overclock get in the way). My 533 DIMMs were budget ram(and they went into another system with my AM2 chip, and its not here anymore so I cant test with them). But my 667 AFAIK is high performance ram (mushkin with a heatspreader, I dont know the model/serial#/etc, but when @ auto and cpu overclocked they run fine@ something like 793mhz so they have decent headroom).

    I would get 800mhz replacements but its not enough of a speed boost to justify...if I could be sure i could also get 800s in dual, that would probably put me over the fence. The only reason I have 667 DIMMS is my old MB only supported 667 or less, but like i said, theyre a high performance matched pair.

    Apache's concerned me now that this: "Due to AMD CPU limitation, DDR2 1066 is supported by AM2+/AM3 CPU for one DIMM per channel only" means ALL ddr2 has single channel support only. Does any one else interpret this that way? Anyone able to confirm or deny this?
  12. No. AM2+ CPUs support DDR2 1066 memory with only one DIMM per channel, but support DDR2 at 800 or less at multiple DIMMs per channel.

    It doesn't matter, anyway, though. Your problem isn't 2 DIMMs in one channel, it's trying to use TWO channels. All that limitation is is that you can't use FOUR DDR2 1066 DIMMs (2 DIMMs in each channel).

    I don't remember reading that you ran Memtest, so run that. If there's errors, you probably need new RAM, if not, see if you can test with some other sticks. If you have some other RAM to test with, please do, if not, the most likely culprit is actually the RAM, so I might replace that first. If that doesn't solve anything, RMA the CPU or Motherboard.
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