5 Replies Latest reply on Jan 18, 2014 9:12 AM by Intelfreak56

    Question about TDP for an intel i5-3570K 77W

    Intelfreak56

      I recently purchased an intel i5-3570k @ 3.4GHZ from newegg for a slight upgrade from my sandy bridge i5 and I have tinkered w/ overclocking it slightly, but not by playing with either the bclk frequency, multiplier or voltages. I simply changed the turbo ratios in the MB bios (UEFI) so that all cores will run at 3.8 when they are active. The question I have is about the TDP listed on the box (as should be 77W) versus what im seeing in the intel gadget monitor utility. When i run(prime95) all cores at 3.8 (and CPUZ does say they are all at the speed), the "PackagePwr0:" reads about 55W. Now that is far lower than the 77W that the processor has listed on the box. So firstly, is that power output accurate (intel power gadget 3.0)? Does it read power delivered the the CPU?  IS that effectively the TDP at that load? And, if this is true, since i can up the core ratios it seems as if there is indeed head room to do so. What is causing that headroom? I don't have the HD graphics 4000 drivers loaded. Might that be the reason why the power is lower? What does the 77W advertised power represent? TDP for the entire chip loaded? As in both the graphics and cpu cores?

       

      Any answers would be appreciated.

        • 1. Re: Question about TDP for an intel i5-3570K 77W
          sylvia_intel

          Hello Intelfreak56, I’m sorry to say that over clocking is not a supported practice from our side and if you are doing so, we are not in position to tell what to expect from the processor.

           

          In regards to the power consumption of this chip, remember that the maximum power this product can draw will be 77W, and it will be for a thermally significant period. If the processor is using only 55W, it does not means the chip is defective, it just mean that the processor is not being used at its 100%

           

          The C-states of the processor are handled by the Enhanced Speed Stepping which allows decreasing the TDP, but all this is auto managed by the processor

          • 2. Re: Question about TDP for an intel i5-3570K 77W
            Intelfreak56

            Please don't put words into my mouth. I really hate that. Also Im not asking your permission to overclock. Intel sold me an unlocked processor so you do fully support my overclocking as it is unlocked (hence the point of a 3570k). And im clearly not asking you to tell me what to expect. The question i was asking was about the power usage being less than 77W. I also dont even remember posting anything about the chip being defective. I asked if the readouts from intels power gadget 3.0 are accurate.

             

            I also asked if the readout is the tdp at that load, which based on your response i assume that it is. So my next question is what is the maximum tdp for just the cores themselves? Is there such a thing? Or does intel not know that.

            • 3. Re: Question about TDP for an intel i5-3570K 77W
              Intelfreak56

              And there should be no problem overclocking the chip because the only thing i did was play w/ the turbo ratios. I haven't disabled turbo or played with any voltage settings (i actually undervolted it a bit). And the chip gets to about 60C max.

              • 4. Re: Question about TDP for an intel i5-3570K 77W
                Codrut Popescu

                I don't know what PackagePwr0: 55W means. TDP is Thermal Design Power which might be different than how much electrical power the CPU is drawing. They are both measured in Watts, butI think that they are not the same. Perhaps this is the cause of confusion....


                Check this:


                "To fully understand what's going on here, you need to understand TDP. In Intel's case, a specified chip's TDP has less to do with the amount of power a chip needs to use (or can use) and more to do with the amount of power the computer's fan and heatsink need to be able to dissipate while the chip is under sustained load. Actual power usage can be higher or (much) lower than TDP, but the figure is intended to give guidance to engineers designing cooling solutions for their products."


                Reference:

                The technical details behind Intel’s 7 watt Ivy Bridge CPUs | Ars Technica

                • 5. Re: Question about TDP for an intel i5-3570K 77W
                  Intelfreak56

                  This is what the product page says:

                   

                  "Thermal Design Power (TDP) represents the near maximum power a product can draw for a thermally significant period while running commercially available software. For thermal solution requirements please consult the Datasheet, volume 1 (where available)."

                   

                  So it does seem that this means "near maximum power" or a point where they reference the max power. And as you say, this power can be more or less, which im fine with. That is far more clear to me now and is more or less what intel should be telling people because they sell them unlocked processors.

                   

                  Wattage is just a unit at the end of the day. Any component that accepts a specific amount needs to, more or less, dissipate the heat that is generated by it. Now this value can be more or less, im sure, but im wondering if intel has any specific info on running the processor w/o the HD graphics. IE Just the processing cores. But i doubt that they will give me any help on that part. However, im ok w/ that because it seems as long as im able to dissipate the heat generated then things shouldn't be a problem because im dissipating far less than what they consider the "thermally significant period". This is why im interested in the PackagePwr readout. It says about 55W, which is far less than 77W. Not that this is a perfectly clean explanation as temperature isn't necessarily evenly distributed throughout the chip, but im certain it is far lower in terms of operating points.