3 Replies Latest reply on Dec 4, 2013 12:34 PM by kevin_intel

    I7 3770K vs 1.65V RAM

    Ivßn Kollßr

      Hi everyone.Now I know this question is asked a lot,but people have different opinions about it so I tought i will ask this in the offical Intel forums.Know I know Ivy Bridge is officialy supports RAMs only up to 1.5V,but as I heard that is becouse the VTT was lowered in the Ivy Bridge CPUs,so if you want to use 1.65V you have to increase your VTT voltage to at least 1.15V.Some people was talking about increaseing VCCSA too,some said that the VCCSA voltage should be left at default.In this guide:http://www.overclock.net/t/1247413/ivy-bridge-overclocking-guide-with-ln2-guide-at-the-end They say this:

      "The voltages you should change for high memory overclocking on Z77 on air is the DDR Voltage, and if you like you can try increasing the VCCIO(VTT) and VCCSA(IMC) the VCCIO (VTT) can help with memory OC, however you will also need to increase VCCSA along with it on these GIGABYTE Z77 boards (except on the Sniper M3). If you want to increase VTT you need to increase IMC voltage to within 0.005v below it, so 1.1v VTT would be 1.095v IMC on these GIGABYTE boards. However I didn't really need to change it much at all."Now the default VTT voltage is 1.064V and the default VCCSA is 0.925 in my BIOS.So that 0.005V difference doesn't seem to be true,but i don't know.I have an Asrock Z77 Extreme 4 mobo and RAMs like this:http://www.valueram.com/datasheets/KHX2000C9AD3T1K2_4GX.pdf

      Two kits,4x2Gb,8 Gb total.Now as you can see it has two XMP Profiles: XMP Profile #1: D3-2000 CL9-11-9-27 @1.65V

      XMP Profile #2: D3-1866 CL9-11-9-27 @1.65V

      Now I bought my 3770k shortly after it released,and I used my RAMs at 1.65V since without issues.Now why do I ask this then?Well recently I updated my BIOS and my settings and profiles were lost and I wasn't sure that increasing the VTT voltage was the only thing I had to do to make it stable,as far as I remember I left VCCSA at default but I'm not sure.The other thing is that they said that 1.65V RAMs can damage the Ivy Bridges IMC in long term...So did i just got lucky that I haven't killed my CPU yet,or I should be fine?Right now I use my XMP profile 1,i have VTT at 1.15V,VCCSA at 0.925V(so default),and everything else is default(not auto,fixed).Except for the core voltage,becouse I overclocked my CPU,and I use LLC level 3 right know,but i guess this is irrelevant to the RAM/IMC.Now of course I'm not looking for an answer like "Intel do not recommend to go above 1.5V" or some offical stuff,I just want to know that am I fine with these settings in the long term for 24/7 use or not.Sorry for this long post,

        • 1. Re: I7 3770K vs 1.65V RAM

          Hi Ivßn Kollßr,


          The information you found may be right but I am afraid that changing the processor settings, increasing or decreasing it is called overclocking and this is not supported by Intel® Due to this reason, the information is not available from our side.


          Intel® 3rd generation processors, as you mentioned, support memory up to 1600Mhz at 1.5v only so using a different memory than this specification can damage the product or a strange behavior can appear.


          My best recommendation is to keep the processor settings and use a memory within the product specifications.

          • 2. Re: I7 3770K vs 1.65V RAM
            Ivßn Kollßr

            What if i use my RAMs at 1866 CL9 1.5V.Not sure if they will be stable,but if they are than that way it shouldn't be a problem for the CPUs IMC and I can leave the VTT at its default value.

            • 3. Re: I7 3770K vs 1.65V RAM

              Hi Ivßn,


              The i7-3770K can handle a memory up to 1600MHz. If you use a faster memory than what the processor can support the performance in the system can be affected and in the worst case the hardware can be damaged.