DDR3 memory: is PC3-10666 compatible with PC3-12800?

17
2014-02
  • AlexV

    OK I have a motherboard which supports DDR3 memory. Currently I have 2 * PC3-10666 2GB in it (4GB total). I plan to remove them and replace them with 4 * PC3-12800 2GB (8GB total).

    My motherboard supports:

    4 x DIMM, Max. 8 GB, DDR3 1600*/1333/800 Non-ECC,Un-buffered Memory Dual channel memory architecture

    *Overclock speed

    Can I safely assume that my new PC3-12800 DIMMs will work with my motherboard (which uses PC3-10666 currently)?

    • Answers
  • skub

    The motherboard specification says it will take 1600 if you overclock. So yes, you can use PC3-12800, since that has a 800 mhz bus speed. The Asus BIOS should over clock it on first boot automatically.

    It's been a while since I've purchased RAM; it didn't click that PC3-12800 is an 800 mhz bus with a 1600 data rate.

    tl;dr = PC3-12800 is 1600 data rate.


    • Related Question

    ASUS M4A79 Deluxe Motherboard & DDR2 800/1066 Memory Compatibility/Limitation?
  • Jonas Gorauskas

    I am looking to buy a ASUS M4A79 Deluxe motherboard at NewEgg and under the specs there is a note regarding the memory standard for this MB. It says:

    Memory Standard:

    • DDR2 1300(O.C.)/1200(O.C.)/1066 * /800/667
    • ECC,Non-ECC,Un-buffered Memory
    • Due to AMD CPU limitation, DDR2 1066 is supported by AM2+ / AM3 CPU for one DIMM per channel only.

    What does the limitation emphasized above means in layman's terms? The MB supports 16 GB of memory and it seems like the only way to max it out is by using DDR2 800 4G modules X 4. Is that a correct assumption? The main use for the system I'm building is as a development workstation that will run several VMs.


    • Related Answers
  • hanleyp

    What it is saying that DDR2 800 and 667 is supported for all 4 DIMM slots. If you use DDR 1066, AMD specifies that DDR2 1066 is specified to work with only 1 DIMM per Channel (2 DIMM slots). If you add more memory or faster memory, then you are going outside the processor manufacturer's specifications (I believe O.C. here stands for "Over Clocking").

    There is mention just under the memory support statement "Refer to www.asus.com for the memory QVL (Qualified Vendors Lists)." This means that Asus has tested specific DIMM modules and have found that they work with this specific motherboard. (Unfortunately, I can't find the QVL for this motherboard on ASUS' website.) The QVL gives information about which DIMM model they used and in which DIMM slots they passed. If a DIMM module is on the AVL as passing and it is greater than 1066 or 1066 with 4 DIMMs populated, then this means ASUS tested it and it works.

    So, your assumed limitation is correct if you select memory not on the QVL.

  • Troggy

    That is a correct assumption. Using an AM2+/AM3 cpu would limit you to two slots if you were using 1066 DDR2. You are correct in how to maximize that mb's ram with 4 - 4gb DDR2 800 sticks.

  • Notorious Arab

    So u would need 4 of these. As Troggy said, you are correct.

    http://www.newegg.com/Product/Product.aspx?Item=N82E16820134863