Results 1 to 9 of 9
  1. #1
    ROG Member Array
    Join Date
    Jul 2018
    Reputation
    33
    Posts
    14

    Question Some cores are hotter than the others - reasons?

    Greetings all,
    I have noticed that on my i7-8700k soe cores are noticably and consistently hotter. For example, below, cores 1,3,5 are hottern that 2,4,6
    Code:
            Core [core-id]  :Actual Freq (Mult.)      C0%   Halt(C1)%  C3 %   C6 %  Temp      VCore
            Core 1 [0]:       4692.69 (46.98x)      99.5       0       0       0    79      1.3440
            Core 2 [1]:       4692.68 (46.98x)      99.5       0       0       0    71      1.3440
            Core 3 [2]:       4692.69 (46.98x)      99.5       0       0       0    80      1.3440
            Core 4 [3]:       4692.70 (46.98x)      99.5       0       0       0    75      1.3440
            Core 5 [4]:       4692.72 (46.98x)      99.5       0       0       0    79      1.3440
            Core 6 [5]:       4692.75 (46.98x)      99.5       0       0       0    69      1.3440
    I wonder what can be the reason? Is it possibly because there are air gaps in some spots left after I applied liquid metal while delidding?

    I also has an idea that this might be due to three cores are just next to the memory controller on the die, as seen on the picture. But I can not verify ifthey are indeed the same core I see running hot.

    Click image for larger version. 

Name:	8700k_die_map_annotated.jpg 
Views:	1 
Size:	203.8 KB 
ID:	74893

    Any other ideas from the community?

    Cheers!

  2. #2
    ROG Guru: Orange Belt Array Rob W. PC Specs
    Rob W. PC Specs
    MotherboardRog Asus Rampage vi extreme
    ProcessorIntel i9-7980x Oc 4.6ghz 24/7
    Memory (part number)64 gb GSkill 3600mhz (8x8) 15,15,15,35
    Graphics Card #1nvidia Titan V + ekwb custom loop
    Graphics Card #2nvidia RTX 2080Ti on air.
    Sound Cardonboard?
    MonitorIAsus PA329Q 4k 32"
    Storage #1samsung SSD 960 EVO 250 GB. M2 nvme
    Storage #2Samsung ssd 970 evo 500gb m2 nvme
    CPU CoolerEKwb custom loop
    CaseCorsair Obsidian 900
    Power SupplyCorsair HX1200i 1200w
    Keyboard Logitech G910 orion spark
    Mouse Logitech G502 Proteus core
    OS Win 10
    Network Routerbt infinity super fast.
    Accessory #1 Seagate Barracuda 2 TB HDD
    Accessory #2 Aqeuaro 6xt fan controller
    Accessory #3 Intel Optane 280gb

    Join Date
    Dec 2015
    Reputation
    104
    Posts
    475

    I had cores running hot, just two or three of them by about ten degrees above the others.
    Same thing, thought it might be the delid so redid it and still same.
    Seems it’s quite a common thing, it can be sorted by going the per core route if it is always the same cores getting hot, lowering the voltage slightly on the offending cores.
    I think it’s down to that silicone lottery pain.*

  3. #3
    ROG Member Array
    Join Date
    Jul 2018
    Reputation
    33
    Posts
    14

    Thanks for sharing your experience! Might save me re-lidding troubles them..
    Other thing - I don't have an option to set different voltages to different cores on my Prime z370-A...

  4. #4
    ROG Guru: Orange Belt Array geneo PC Specs
    geneo PC Specs
    MotherboardMaximus X Code
    ProcessorIntel 8086K @ 5.1Ghz
    Memory (part number)32 GB (2x16) G.Skill TridentZ RGB 3200 MHz CL14 @ 3733 16-16-36
    Graphics Card #1MSI GTX 1070 X 8GB
    Graphics Card #2AMD Radeon WX 7100
    MonitorNEC PA271Q and Dell
    Storage #1Samsung 512 GB 960 Pro
    Storage #21TB 850 x 1 TB 860 EVO RAID 0, 6 TB WDC Black HDD
    CPU CoolerNoctua NH-D15 Chromax
    CaseFractal Design R4 w/ tempered glass
    Power Supply750W Seasonic Prime Ultra Titanium
    Keyboard CM Quickfire Rapid TKL
    Mouse G602
    Headset Bose
    Headset/Speakers Vanatoo T1, ML Dynamo 300
    OS Windows 10 Pro X64
    geneo's Avatar
    Join Date
    Feb 2014
    Reputation
    27
    Posts
    364

    Variations in the accuracy of the heat sensors among other things.

  5. #5
    Administrator Array Silent Scone@ASUS's Avatar
    Join Date
    Mar 2016
    Reputation
    124
    Posts
    1,799

    As has been said already, core temperature variance is normal, on some platforms up to 20c is not uncommon.

  6. #6
    ROG Guru: Yellow Belt Array XYchromosone PC Specs
    XYchromosone PC Specs
    Laptop (Model)DELL Inspiron 15 5559 + HP Pavilion dv6 3032tx
    MotherboardASUS Maximux XI Extreme [BIOS 1105]
    Processori9 9900K
    Memory (part number)Corsair Vengance RGB 16GB CMR16GX4M2C3466C16 V4.31
    Graphics Card #1ASUS ROG Strix Gaming GTX1080Ti 11GB
    MonitorAOC AG271QG 27" 165Hz
    Storage #1Samsung 970 Pro NVMe 1TB M.2 SSD
    CPU CoolerThermaltake Floe Riing 360 Premium AIO
    CaseFractal Design Define R6 Black
    Power SupplyCorsair AX1600i
    Keyboard RAZER Blackwidow X Tournament Chroma
    Mouse RAZER Lancehead [ambidextrous] Chroma
    Headset Sennheiser RS165 Wireless
    OS Windows 10 Pro x64 + UbuntuStudio 18.04
    Network RouterASUS DSL-AC68U on ADSL2+, Technicolor DJA0230TLS Gateway NETGEAR CABLE ADAPTER CM450
    XYchromosone's Avatar
    Join Date
    Dec 2015
    Reputation
    30
    Posts
    152

    Quote Originally Posted by metadist View Post
    Other thing - I don't have an option to set different voltages to different cores on my Prime z370-A...
    I am not aware of any motherboard that allows per core voltage control if you use a manual voltage, possible the "Adaptive" or "Offset voltage" control would control a per core voltage, though.

    However a possible option is to set a per core multiplier and have the core[s] that run hotter set to a lower multiple. E.g., let's say if cores 4 and 5 are always showing that these 2 cores run much hotter than the rest of the cores when you have a voltage set manually, you can set a per core multiplier of :

    Core 0 x 48
    Core 1 x 48
    Core 2 x 48
    Core 3 x 45
    Core 4 x 45
    Core 5 x 48

    This is just an example, but you might need to experiment with this including core voltage. You could see how a manual voltage of let's say v1.25 to v1.30 affects those 2 cores in a benchmark. Then try an Adaptive voltage setting etc. and see how which setting affects the cores temps in a benchmark under load.

    As and end note, a build I did last year with a Maximus VIII Ranger mobo running an i7 6700 non K CPU one of the 4 cores ran about 20 deg hotter than the 3 other cores. This was pretty well at all times, especially when a little load was put on the CPU. I was tempted to do a delid just to satisfy my curiosity, but since it wasn't a K model CPU I decided to not go ahead with it. SO whether it was due to an uneven layer of heatsink compound on the CPU die or something else that was causing this heat differential with a single core, I will never know.

    It goes to show that it can and it does happen. The thing that matters to me is does it affect the lifespan of that core, which effects the lifespan of the cpu, OR the work it can do under load when power throttling cuts in due to overheating that core, lowering the overall score in a benchmark test etc.
    Last edited by XYchromosone; 08-25-2018 at 05:11 AM.

  7. #7
    ROG Enthusiast Array
    Join Date
    Apr 2016
    Reputation
    11
    Posts
    37

    In my experience with the 8700K I got, the temperature variance between cores was +-10C before delidding. After delidding, the variance went down to about 4~6C.

  8. #8
    ROG Guru: Yellow Belt Array XYchromosone PC Specs
    XYchromosone PC Specs
    Laptop (Model)DELL Inspiron 15 5559 + HP Pavilion dv6 3032tx
    MotherboardASUS Maximux XI Extreme [BIOS 1105]
    Processori9 9900K
    Memory (part number)Corsair Vengance RGB 16GB CMR16GX4M2C3466C16 V4.31
    Graphics Card #1ASUS ROG Strix Gaming GTX1080Ti 11GB
    MonitorAOC AG271QG 27" 165Hz
    Storage #1Samsung 970 Pro NVMe 1TB M.2 SSD
    CPU CoolerThermaltake Floe Riing 360 Premium AIO
    CaseFractal Design Define R6 Black
    Power SupplyCorsair AX1600i
    Keyboard RAZER Blackwidow X Tournament Chroma
    Mouse RAZER Lancehead [ambidextrous] Chroma
    Headset Sennheiser RS165 Wireless
    OS Windows 10 Pro x64 + UbuntuStudio 18.04
    Network RouterASUS DSL-AC68U on ADSL2+, Technicolor DJA0230TLS Gateway NETGEAR CABLE ADAPTER CM450
    XYchromosone's Avatar
    Join Date
    Dec 2015
    Reputation
    30
    Posts
    152

    @jologskyblues I take it from what you say is that there was/is an AVERAGE temp variance between all 6 cores, which is normal. There will [always] be variation in temperature between all the cores in a multi-core CPU because the load the OS puts on the CPU varies between each core. I'm guessing you already know that.

    However, this thread is about just one or two cores always running hotter by a good margin, than the rest of the cores, e.g. in my case with an i7 6700 one core ran hotter even at idle under no load by a good margin. This is definitely an indication that something is not 100% right with CPU either at the silicon level or something to do with the thermal paste intel uses or its application [air pockets left between the die and CPU lid e.g.].

    But I do understand how the delid helped to reduce the temperature of the CPU as you explained, which would effect the temp variation % between all the cores to be less, I'd think.

  9. #9
    ROG Enthusiast Array
    Join Date
    Apr 2016
    Reputation
    11
    Posts
    37

    @XYchromosome

    To clarify my statement, the temperature variance I was mentioning is specifically the difference in temperature between the hottest core and the coolest core when fully stressed in Realbench, x264, Prime95, etc.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •