Optiplex 780 & 8GB DDR2 800MHz?

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Optiplex 780 & 8GB DDR2 800MHz?

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Hi!

I'm the owner of an Optiplex 780 with 2GB DDR3 @ 1066MHz. I have 8GB (2GBx4) DDR2 @ 800MHz from an older computer, can I use DDR2 memory in this machine? Could DDR3 @ 1600MHz dimms works too?

Thanks.

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DELL XPS M1330 Black
Intel Core 2 Duo T9300 2.5GHz, 4GB DDR2 667MHz, 250GB HDD, nVidia 8400M GS 128MB GDDR2

DELL Optiplex 755 MT
Intel Core 2 Quad Q9650 3.0GHz, 8GB DDR2 800MHz, 320GB HDD, ATI HD5670 1GB GDDR5

Verified Answer
  • The advice Robin gave is correct.

    DDR2 won't physically fit into a DDR3 slot, so unfortunately no. Even if the Dell documentation didn't specify, that alone would nullify the possibility.
    As far as DDR3 1600MHz RAM: the board will, at most, support 1067MHz. The 1600MHz RAM, even if recognized by the board, wouldn't run at 1600MHz. Most probably though your Dell wouldn't POST with the 1600MHz RAM installed.

    Dell:
    XPS 720 Red/Silver ATX mod - Athlon II X3 3GHz, 8GB Kingston HyperX, 128GB Kingston SSD, 500GB+2x1TB Seagate, HD5770 x2
    ZinoHD Tomato Red - Athlon X2 1.5GHz, 4GB Kingston Platinum, 500GB Seagate, HD4330M
    Mini 1012 Cherry Red - Intel Atom 1.66GHz, 2GB Kingston Platinum, 64GB Kingston SSD
    S2230M 21.5" 1080p LED monitor

    Other:
    HTC Arrive
    Zune HD 16GB
    HP Touchpad 32GB

    Fan of: AMD CPUs, XFX GPUs, Seagate HDDs, Kingston RAM & SSDs

All Replies
  • Hi navaro's, Having looked at your manual HERE, it says you can only use the DDR3 1067MHz.

     

          

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  • The advice Robin gave is correct.

    DDR2 won't physically fit into a DDR3 slot, so unfortunately no. Even if the Dell documentation didn't specify, that alone would nullify the possibility.
    As far as DDR3 1600MHz RAM: the board will, at most, support 1067MHz. The 1600MHz RAM, even if recognized by the board, wouldn't run at 1600MHz. Most probably though your Dell wouldn't POST with the 1600MHz RAM installed.

    Dell:
    XPS 720 Red/Silver ATX mod - Athlon II X3 3GHz, 8GB Kingston HyperX, 128GB Kingston SSD, 500GB+2x1TB Seagate, HD5770 x2
    ZinoHD Tomato Red - Athlon X2 1.5GHz, 4GB Kingston Platinum, 500GB Seagate, HD4330M
    Mini 1012 Cherry Red - Intel Atom 1.66GHz, 2GB Kingston Platinum, 64GB Kingston SSD
    S2230M 21.5" 1080p LED monitor

    Other:
    HTC Arrive
    Zune HD 16GB
    HP Touchpad 32GB

    Fan of: AMD CPUs, XFX GPUs, Seagate HDDs, Kingston RAM & SSDs

  • Thanks for the replies.

    The fact is this, I can get 1066 and 1600 MHz DDR3 memory from the same brand, model and specifications at the same price. My question is: Can I use 1600 MHz memory working @ 1066 MHz in this computer? I think could be more useful the 1600 MHz memory to reuse it in the future.

    Thanks.

    ∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞

    DELL XPS M1330 Black
    Intel Core 2 Duo T9300 2.5GHz, 4GB DDR2 667MHz, 250GB HDD, nVidia 8400M GS 128MB GDDR2

    DELL Optiplex 755 MT
    Intel Core 2 Quad Q9650 3.0GHz, 8GB DDR2 800MHz, 320GB HDD, ATI HD5670 1GB GDDR5

  • You can only if you leave at least one of the 1066MHz chips in. If you use all 1600MHz then they won't down-clock to the 1066MHz speed otherwise.

    Dell:
    XPS 720 Red/Silver ATX mod - Athlon II X3 3GHz, 8GB Kingston HyperX, 128GB Kingston SSD, 500GB+2x1TB Seagate, HD5770 x2
    ZinoHD Tomato Red - Athlon X2 1.5GHz, 4GB Kingston Platinum, 500GB Seagate, HD4330M
    Mini 1012 Cherry Red - Intel Atom 1.66GHz, 2GB Kingston Platinum, 64GB Kingston SSD
    S2230M 21.5" 1080p LED monitor

    Other:
    HTC Arrive
    Zune HD 16GB
    HP Touchpad 32GB

    Fan of: AMD CPUs, XFX GPUs, Seagate HDDs, Kingston RAM & SSDs

  • So, if I want 8GB I must get 1066 MHz memory because 4 dimms 1600 MHz won't work, Am I wrong?

    ∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞

    DELL XPS M1330 Black
    Intel Core 2 Duo T9300 2.5GHz, 4GB DDR2 667MHz, 250GB HDD, nVidia 8400M GS 128MB GDDR2

    DELL Optiplex 755 MT
    Intel Core 2 Quad Q9650 3.0GHz, 8GB DDR2 800MHz, 320GB HDD, ATI HD5670 1GB GDDR5

  • No, you are correct. You will need 8GB (4 sticks of 2GB) of 1066MHz.

    Dell:
    XPS 720 Red/Silver ATX mod - Athlon II X3 3GHz, 8GB Kingston HyperX, 128GB Kingston SSD, 500GB+2x1TB Seagate, HD5770 x2
    ZinoHD Tomato Red - Athlon X2 1.5GHz, 4GB Kingston Platinum, 500GB Seagate, HD4330M
    Mini 1012 Cherry Red - Intel Atom 1.66GHz, 2GB Kingston Platinum, 64GB Kingston SSD
    S2230M 21.5" 1080p LED monitor

    Other:
    HTC Arrive
    Zune HD 16GB
    HP Touchpad 32GB

    Fan of: AMD CPUs, XFX GPUs, Seagate HDDs, Kingston RAM & SSDs

  • OK, thank you very much.

    ∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞

    DELL XPS M1330 Black
    Intel Core 2 Duo T9300 2.5GHz, 4GB DDR2 667MHz, 250GB HDD, nVidia 8400M GS 128MB GDDR2

    DELL Optiplex 755 MT
    Intel Core 2 Quad Q9650 3.0GHz, 8GB DDR2 800MHz, 320GB HDD, ATI HD5670 1GB GDDR5

  • You can use 4GB sticks in  a 780 but you need to update BIOS to A05, and 1333 and 1600 both clock down to 1066... its a MB/Chipset limitation

  • Okay, now I'm TRULY confused - you said he can use 1600 *IF* he leaves in some of the 1066 sticks, so your own answer is wrong - you said, "No, you are correct. You will need 8GB (4 sticks of 2GB) of 1066MHz."

    But, from  your earlier answer, it seems that he could have 2 x 1066 2GB sticks; and 2 x 1600 2GB sticks, for a total of 8GB, and it would down-clock to the lower memory speed - right?

    If so, then NO, he does not have to get 4 x 8GB 1066; he can get 2x1066 and 2x1600.

    I'm with him - I am seeing some REAL deals on the 1600 memory, and I could care less if it down-clocks, I just need the extra memory - plus, he make an excellent point about using it in future upgrades - great way of thinking ahead!

  • A bit of clarification: He said it will down-clock IF you leave 1066 chips in, so it would seem you could do 2x1600 + 2x1066 and you would be fine. From my experience, you don't have to match all 4 of the memory sticks - just match "each pair." 2 black slots = 1 speed, and then 2 white slots = the other speed.

    And, as far as putting ALL 1600 memory in, his answer is "just a [guess]," since he hasn't tried it. Some system in the past would allow ALL sticks to be 'faster memory,' but would not go any faster than their spec - i.e. 1066 in this case.

    Regarding these newer - 780, 790, 960 systems, I don't know how that would work - or IF it would work; but, from my own experience (in the past, not with 1066/1600 [I have 1066 in my 780),  mixing slower + faster was okay, as long as you matched each pair (2x1600 & 2x1066, for example).