1 Reply Latest reply on Mar 26, 2012 3:02 AM by parsec

    Can I use 1.5v and 1.35v on DP55WB at same time?


      I have 8GB =  4 x 2GB DDR3 1333 7-7-7-21 1.5vin there now.


      Which is better to use: 1.35v or 1.5v? And can I mix them?

      I'm thinking lower voltage, lower power consumption, less heat - longer life???


      I would like to update - replacing 2 of the 2GB with 4GB DDR3 1333 7-7-7-21 1.35v

      so the end result would be

      Channel A

      DIMM 0     4GB DDR3 1333 7-7-7-21 1.35v

      DIMM 1     2GB DDR3 1333 7-7-7-21 1.5v


      Channel B

      DMM 0     4GB DDR3 1333 7-7-7-21 1.35v

      DMM 1     2GB DDR3 1333 7-7-7-21 1.5v


      Would this work or do I need to use all 1.35v or all 1.5v?  The manual states < 1.65v, but does not state which voltages are supported. A memory web-site states 1.35 works).  Would prefer to update to 12GB total instead of 8GB.  I tried overclocking some to 3.0 GHz for a couple weeks, but ended up sticking around 2.8 as it is fast enough, runs cooler and had very rare 'I wonder if over-clocking did that' events a few too many times.

      Would hate to buy the 1.35 and find out they all have to be the same voltage too late.







      SW: Windows 7 SP1 Ultimate - 64-bit, VS 2010, some medium graphics games

      HW:  I7 860 @ 2.8GHz, 8GB DDR3. 3+TB HD, GTX 250 video

        • 1. Re: Can I use 1.5v and 1.35v on DP55WB at same time?

          The main answer you need is, there is only one voltage setting in your BIOS for ALL the DIMMs in a PC. You cannot set the voltage for each individual DIMM slot, as you proposed. You can only set all the slots to 1.5V, or 1.35V, etc.


          The maximum voltage for the memory of your board/CPU is 1.65V. You can set it to almost anything lower than that, with some restrictions. In some BIOS', you can increase or decrease the memory voltage in pre-defined steps, for example 0.01V for each step. This is really not an issue in your situation.


          Using memory DIMMs, sticks, or cards that match each other has become more important with each new generation of CPUs. I have mixed DIMMs from two different manufactures, and slightly different voltages, in a socket 775 board, but that would never work on a socket 1366 board, or anything newer than that. Your socket 1156 board might be in between those two, but I've never owned one so I don't know how picky they are about mixing memory. I hope all this memory is made by the same company and the same basic model, otherwise it most likely won't work together.


          You MIGHT be able to run the 1.35V memory at 1.5V, or run the 1.5V memory at a slightly lower voltage, but you must check the specs for each memory type. What is the max voltage the 1.35V memory will work with? Is there a minimum voltage spec for the 1.5V memory? Can you run those two at 1.4V?


          Really the best and easiest solution is simply using memory of all the same voltage, and exactly the same type. So all 1.5V, or all 1.35V, but mixing them is pure luck if it works.


          Memory uses very little power really, and really should not get hot unless it's voltage is increased above it's rating.