11 Replies Latest reply on Feb 5, 2018 5:52 PM by Al Hill

    Is 7700K's supported memory speed derived from clock speed or architecture?

    christmascheer

      So the intel 6700K has a max supported RAM speed of 2133Mhz. The 7700K has a max supported RAM speed of 2400Mhz.

       

      If I significantly underclock/undervolt a 7700K, will it still natively support the 2400Mhz memory speed?

       

      Understanding what is the cause of its higher supported memory speed will also help me understand this. From what I can tell, the 7700K has no significant architectural changes from the 6700K. If it is instead the 7700K's higher clocks that allows higher memory speeds, then will underclocking the 7700K reduce the supported memory speed?

       

      The only reason I would buy the 7700K is to natively support 2400Mhz RAM without overclocking.

        • 1. Re: Is 7700K's supported memory speed derived from clock speed or architecture?
          N.Scott.Pearson

          First of all, understand that the Maximum Supported DRAM Speed does not imply that faster DRAM speeds are not going to work. For the most part, it just means that Intel is not formally testing faster DRAM speeds and (thus) does not guarantee that they will work. Remember that using faster DRAM speeds is technically considered a form of overclocking and could result in portions of the processor running at higher temperatures.

           

          Undervolting should not affect the DRAM bus speed. Underclocking, on the other hand, correspondingly slows the supported speed of the DRAM bus.

           

          Hope this helps,

          ...S

          • 2. Re: Is 7700K's supported memory speed derived from clock speed or architecture?
            christmascheer

            "First of all, understand that the Maximum Supported DRAM Speed does not imply that faster DRAM speeds are not going to work. For the most part, it just means that Intel is not formally testing faster DRAM speeds and (thus) does not guarantee that they will work. Remember that using faster DRAM speeds is technically considered a form of overclocking and could result in portions of the processor running at higher temperatures."

             

            Right, by supported RAM I mean "will run without overclocking." This is why I'm interested in a processor that can run the 2400Mhz RAM I own without overclocking.

             

            "Undervolting should not affect the DRAM bus speed. Underclocking, on the other hand, correspondingly slows the supported speed of the DRAM bus."

             

            Thank you. To clarify, you're saying it is indeed the 7700K's higher clock speed which allows for 2400Mhz memory support over 2133Mhz, and that by underclocking, I'd be turning the 7700K into a 6700K? Do you think the speed of the DRAM bus decreases in set units, like from 2400 > 2133? Or are there speeds in between that could be compromised?

            • 3. Re: Is 7700K's supported memory speed derived from clock speed or architecture?
              N.Scott.Pearson

              No, I am saying that! They simply chose to validate up to 2400 MHz on this newer processor. Don't read so much into the warning or into the fact that Intel postures this as technically being overclocking; the higher temperatures are likely almost insignificant and should not affect the lifetime of the processor (Intel would saying a hell of a lot more about this if this was really a significant issue).

               

              No, I am NOT saying that the processor's higher clock speed has anything to do with the decision (their clock speeds are essentially the same; maybe some differences in the Turbo clocks, but this is related to temperatures more than anything else). Underclocking is NOT going to turn a 7700K into a 6700K; there *ARE* significant architectural differences between these processors. Internal to the processor, there are complex relationships between the speeds of the various buses and the underclocking of one will most likely have some form of proportional relationship on the others - so no, the DRAM bus speed will not drop in set units. A significant drop in DRAM clock speed could require changes in multipliers, wait-states, etc.

               

              I am not trying to be insulting but I do have to be honest: you do not sound like you understand this stuff enough to be playing with overclocking, underclocking, overvoltaging or undervoltaging. You better think very carefully before making any changes of any kind.

               

              ...S

              • 4. Re: Is 7700K's supported memory speed derived from clock speed or architecture?
                christmascheer

                Who said I'm playing?

                 

                Ok, let's try this again. In response to the thread title: "Is 7700K's supported memory speed derived from clock speed or architecture?" Your replies suggest the answer is, essentially both. You've said that the 7700K has significant architectural changes from the 6700K, and that they chose to validate 2400Mhz on the 7700K. You've also said that underclocking would consequently result in a proportional decrease in DRAM bus speed.

                 

                Is Intel's choice to "validate" the higher memory speed a capability of the new architecture, or is it just a number that they changed for the 7700K? What you mean by validate is at the heart of my question here.

                • 5. Re: Is 7700K's supported memory speed derived from clock speed or architecture?
                  N.Scott.Pearson

                  No, it is neither. Don't try to read between my words! If I don't explicitly say it, I am not suggesting it.

                   

                  Their decision to validate 2400MHz was purely a balance between their desire to support the higher bus speeds that end users are (always) asking for and the resources - head count, time and money - that they will need to perform this validation. Plain and simple, Intel will warranty no solution that they don't exhaustively validate.

                   

                  ...S

                  • 6. Re: Is 7700K's supported memory speed derived from clock speed or architecture?
                    christmascheer

                    Actually, both your responses clearly implicated that the clock speed and architecture were responsible for the higher memory speeds. The lack of clarity is on your end. My last question was, what does it mean to "validate" the higher memory speed, and you still haven't answered this.

                    • 7. Re: Is 7700K's supported memory speed derived from clock speed or architecture?
                      N.Scott.Pearson

                      No, nothing I said implied that; you read what you wanted into it.

                       

                      As far as validation is concerned, substitute "test" if you like.

                       

                      ...S

                      • 8. Re: Is 7700K's supported memory speed derived from clock speed or architecture?
                        christmascheer

                        Incorrect. You can scroll up to see your reply where you say that underclocking limits the DRAM bus speed. Consider not engaging with the question next time, since receiving no response would objectively be more helpful to me.

                        • 9. Re: Is 7700K's supported memory speed derived from clock speed or architecture?
                          N.Scott.Pearson

                          No, not incorrect. You did it again; you made another bad presumption. The 6th gen and 7th gen processors are both capable of operating their memory buses at much higher speeds and neither is really any better than the other at doing so. Intel chose to validate the 7th gen processors to 2400MHz because customers were asking them to do so, not because they are any better at running at 2400MHz (because they are really not). Both the 6th and 7th generation processors, if matched with well-designed and high-build-quality boards, are (IMHO) equally capable of running with, say, 3200MHz memory.

                           

                          I am giving you the right information. You are simply not properly interpreting that information because of your preconceptions. You are struggling to identically match apples with oranges and you simply cannot.

                           

                          It is certainly true that the underclocking of the main processor buses will result in an underclocking of the memory buses -- but this is equally true for both the 6th generation and 7th generation processors. The fact that Intel is validating the 7th generation processors at 2400MHz has nothing to do with any additional capability that the 7th generation processors present.

                           

                          ...S

                          • 10. Re: Is 7700K's supported memory speed derived from clock speed or architecture?
                            christmascheer

                            I didn't say it was different for 6th and 7th generation processors. I'm simply saying, that despite your insistence that I was misinterpreting you, you said in your reply, that underclocking the 7700K would limit the speed of the computer's memory-- which, when looking at the question in the title of this thread, would make "clock speed" a valid answer.

                            • 11. Re: Is 7700K's supported memory speed derived from clock speed or architecture?
                              Al Hill

                              Christmascheer, this discussion is now pointless.  You have received an answer.  At this point, you are arguing needlessly.

                               

                              Discussion locked.

                               

                              Doc