10 Replies Latest reply on Feb 10, 2010 12:08 PM by Eandori

    DP55KG - Random reboots


      As the title says, my computer will randomly reboot.  Screen goes black, back to post screen.  It's not a software issue, as it's happened on all the OSes I've had installed on this computer so far.  Someone suggested I try reseating the ram, and I did so, moving the cards around in the slots. It seemed to make my computer reboot even more often.  I ran memtest, and it didn't find any errors (only ran it to 30% though, don't think that matters).


      A friend is suggesting that I try using the bios reset switch (the little pin thing, I don't know what it's called), as he says he had a similar problem that was solved by doing this.  Before I try this, is it a good idea?  I litterally JUST flashed the bios to the most recent one so I wouldn't THINK that it would help, but...


      Video card is recycled from my old computer, so I suppose that could be contributing....



      i5 750

      6 gig RAM (don't remember what it was advertised at, but bios says it's running at 1333)


        • 1. Re: DP55KG - Random reboots

          Check the timing of your RAM module in the bios with that specified by the manufacturer. Also check the ram voltage setting.

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          • 2. Re: DP55KG - Random reboots

            The statistics of my ram on newegg are 1600MHz, 9-9-9-24 and 1.65 volts


            Bios says:

            multiplier: 10

            Speed: 1333

            Uncore Multiplier: 16

            Uncore Speed: 2.13Ghz

            Voltage: 1.5V


            I've been too lazy to overclock in the past, and as such I dont know much about doing so, but I wouldn't think that having my ram at a lower clock speed would inversely affect stability.

            • 3. Re: DP55KG - Random reboots

              Looking at the specification of your ram and the bios setting there is an incompatibility. I'm not sure if this will work in your case since your processor only support 1066/1333 Mhz Ram but your ram is rated at 1600 Mhz. Try adjusting the voltage in the bios to 1.6v - 1.64v if possible.

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              • 4. Re: DP55KG - Random reboots

                Went to change the performance settings on the memory and it said it had a profile for "XMP 1600"  that when I picked it, changed a bunch of options, including setting the voltage to 1.65 and the clock rate to 1602.  Unfortunately when I booted it, it wouldn't post, rebooted with a screen telling me such with a prompt to go to the bios to change my settings.


                Went back in, hit the "default settings" button, changed the ram voltage to 1.62 and it booted up fine.  Still running at 1333 though.  Will let you know if I have any further problems in a few hours.

                • 5. Re: DP55KG - Random reboots

                  Your processor supports up to 1333 Mhz only (i5-750) so that it is okey. It is not advisable to overclock although it's possible. Let's just hope that changing of the ram voltage solves the problem of blue screen and reboots.

                  • 6. Re: DP55KG - Random reboots

                    Just left my computer on all night as a test and it still hasn't rebooted.  Before it wouldn't last more than three hours.


                    Thanks, Boyet!

                    • 7. Re: DP55KG - Random reboots

                      You're welcome. Glad to hear the good news.

                      • 8. Re: DP55KG - Random reboots

                        Glad to see you got this worked out.  Yeah, P55 boards (made for core i3, i5, socket 1156 core i7...) were intended to be used with 1.5v DDR3 RAM.  That is the default voltage.  Many memory vendors literally just overclock their own memory, which requires up to 1.65v to run stable and sell it as "1600 DDR3 RAM" when in fact, it's really just 1333 sold as pre-overclocked without telling you that.


                        It's also important to note that going above 1.65v for your Memory voltage is risky on P55 chipset boards... don't do it unless you are willing to risk your hardware.



                        • 9. Re: DP55KG - Random reboots

                          question here -- my memory is set to 1.5v, sounds familiar, I'm guessing the poster might have Gskill memory (Ripjawz?) since the timings/voltage/XMP profile matches up to what I use.


                          my question though, is: is the memory voltage tied in any way to anything else, such as the uncore voltage? i'm still kind of in the dark as to what exactly the "uncore voltage" actually is (other than... it's not the CPU voltage) -- for instance, if uncore voltage was increased, would that increase the memory voltage, or is it just straight "memory voltage = memory voltage"?


                          for instance, my "uncore voltage" currently is set (by default) to 1.1v. when i go into the desktop control center, then into "monitoring", on the red/yellow/green gradient gauge, it shows that my current 1.1v as in the border between yellow and red -- i'm not going to touch anything since as I mentioned in other posts, I'm in the process of RMA'ing my CPU already, I do not feel comfortable adjusting any of this, but I'm wondering: Is this "low voltage" something to be concerned about, or does it dynamically fluctuate (like CPU voltage during low-power states)?


                          I don't get worried when the CPU goes down to approximately the same area (yellow/red gradient border) because I know voltage is dropped when CPU cores are idle, causing this "low voltage" state (which is intentional, and not really "dangerous", as the scale may seem to indicate)


                          What about PCH voltage? What would that need to be upped for?


                          So essentially, I'm asking "for what reason(s) would uncore and/or PCH voltages need to be increased, and in increasing these voltages, do they have any cascading effect on other components? If so, what components do changes in uncore voltage affect, and what components do changes in the PCH voltage affect (aside from the actual PCH)?

                          • 10. Re: DP55KG - Random reboots

                            The CPU has both the core, and the uncore inside the same package.  As you can see on P55 boards there is just 2 major chips.  CPU and PCH, where older boards all had 3 chips (CPU, MCH, ICH).  Basically, the memory controller is now a part of the CPU package and it's called the "UnCore" because it's literally not part of the core CPU.  Since it's the memory controller, it has some form of sharing voltages with the actual memory voltage which is why going above 1.65v is a little dangerous.


                            Core i7, i5, and i3 CPU's have a dynamic voltage control ability inside the package itself.  They can actually increase or decrease their own voltage as they see fit.  So at any one moment if you were to measure the actual voltage going into the CPU it might be slightly different then another moment.  It's not static like CPU's in the past were.  This is a feature to save power, keep temp down, etc.  It's a very good thing and I give the CPU team huge props for it.


                            My reccomendation is unless you are looking to over-voltage, don't change the voltage settings to the Core/UnCore at all.  Just leave it on default.  But if you are bumping up your BClock or doing some other form of overclocking, that's when you might want to increase the Core/UnCore/Memory voltage rails.  In my own internal development testing of DP55KG I got some very solid and stable benchmarks from this profile (With a very nice power supply, 2.93 CPU, DDR3 1600 RAM, and upgraded CPU heatsink)


                            BClock: 180MHz

                            V-Core: 1.35v

                            V-UnCore: 1.35v

                            V-Memory: 1.65v

                            Memory Multiplier: 10 (Load XMP profile, then set the profile back to Manual and multiplier back to 10)

                            TurboMode: Disable (Turbo mode is RAD on normal settings, but when pushing all cores to the peak Turbo mode and push a single core too far and cause a failure)


                            On my setup, I got huge OC Benchmark scores with that setup.  If you want to try it, I suggest slowly increasing to that value and testing on each step to make sure you are still stable.