Detailed study on AS5 break-in time; it only takes a few hours

Discussion in 'Overclocking, Cooling & Modding' started by graysky, Dec 3, 2014.

  1. graysky

    graysky ARP Reviewer

    According to the manufacture of AS5, there can be up to 200 hours of break in time required for temps to stabilize. This claim has been tested the results are shared in this thread.

    Materials, software, and experiment
    A delidded i7-3770k (over-clocked to 44x100 with fixed vcore) was treated with a fresh line of AS5 both under and above the IHS per the manufacture recommended procedure for application to Ivybridge i7 chips (see above link). The Intel stock HFS was then attached and the system was stressed using either mprime (prime95 for Linux) or burnP6 immediately after the HSF was seated to establish as baseline (time = 0) steady-state temperature for each stresser.

    Core temperatures, vcore, and CPU fan RPMs were measured using a simple shell script harvesting the linux kernel's lm_sensors readings. Ambient temperature also also recorded using the average of two external thermometers.

    Once the baseline temps were established, the experiment was conducted as follows: the stress tests were repeated every 2 hours for several days. This means 42 min of stress (12 min for burnP6 and 30 min for mprime) followed by 78 min of idle all day everyday for 3 days. Then the interval was lengthened to once every 4 hours (42 min of stress, 198 min of idle) for a few days. Finally, the interval was lengthened to once every 6 hours (42 min of stress, 318 min of idle) for the rest of the experiment.

    The resulting data were normalized to the average readings for the initial run in order to study the temperature decrease and rate of decrease.

    Mprime version 28.5 x86_64 running 8 threads preforming a FFT of size 440k.
    cpuburnP6 has no settings for multiple cores but it was run in 8 independent processes so all cores would be stressed equally.

    [​IMG] [​IMG]

    The temps basically stabilize after 8 hours -- no where near the 200 hours the manufacture claims -- in this particular test. The magnitude of the decrease was 3-4 C relative to the initial temps depending on the stress methods which is pretty good. How general is this result? The hallmark of a scientific experiment is a reproducible outcome. This is just an n of 1 but no plans are in the works to repeat the experiment. Perhaps others will do it and report back. Feel free to use this thread if you do.

    Extra details
    Calculating zero
    Zero was calculated simply by stressing with the program (either mprime or burnP6) and waiting for the temps to stabilize. In the plot of core temp adjusted for ambient vs. time (seconds), the pink color indicates data points I excluded since the CPU was coming up to temperature while the blue color denotes datapoints that were included. The higher temp/shorter line is the temperature profile for burnP6 and the lower temp/longer line is the profile for the mprime run. Basically, cpuburnP6 was run for 12 min and mprime for 30 min, excluding the first 400 sec from each one. The 2nd plot just shows the same data unnormalized for ambient temp and split out by individual core:


    This plot shows the time since the HFS was seated (days) vs. delta temperature "dT" above ambient for each of the stress programs. Initially, they were run every 2 hours, but after 3 days or so, the interval was lengthened to every 4 hours, and finally to every 6 hours until approx 200 hours had elapsed. Both stress programs gave similar results with the average temp drop occurring sometime around 8 hours and stabilizing around 3-4 degrees less than the initially measured temps.

    The first plot shows the average of all cores and the 2nd one shows the values for the individual cores.

    Data table
    The data table generated by the script linked above is available in csv format. A more elaborated table where I preformed some calculations needed for the plots (difference from ambient temp, which points are included or excluded, average for time=0 for each stresser, etc) is also available in csv format should you wish to plot anything yourself.
    Last edited: Dec 6, 2014
  2. ET3D

    ET3D Newbie

    Thanks a lot for that Arctic Silver link. I had no idea there were recommended spreads for different processors. Now I know.

    And thanks for the interesting experiment.
  3. Adrian Wong

    Adrian Wong Da Boss Staff Member

    Do you mind if I adapt and post it in Tech ARP, graysky? :mrgreen:
  4. graysky

    graysky ARP Reviewer

    Go for it. I'll probably keep it collecting data for another week or so and will update the images as well as post the entire data table.
  5. Adrian Wong

    Adrian Wong Da Boss Staff Member

    Thanks! :thumb: :thumb:
  6. Adrian Wong

    Adrian Wong Da Boss Staff Member

  7. graysky

    graysky ARP Reviewer

  8. graysky

    graysky ARP Reviewer

    OK, ran out to ~200 hours and as expected, no change. Updated original post and linked data table. You might wanna re-write your article, Adrian. I also re-worded my post in the 3rd person which is a little more professional sounding if that matters :p
  9. Adrian Wong

    Adrian Wong Da Boss Staff Member

    No problem. Thanks!! :thumb:
  10. Max_87

    Max_87 huehuehue

    Off topic, how much improvement did you get for delidding your Ivy chip?
  11. graysky

    graysky ARP Reviewer

  12. Adrian Wong

    Adrian Wong Da Boss Staff Member

  13. graysky

    graysky ARP Reviewer

    Looks good :)
  14. Adrian Wong

    Adrian Wong Da Boss Staff Member

    :thumb: :thumb: :mrgreen:

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