Comparison of AS5 vs. MX-4 on Haswell i7-4790K

I compared Arctic Silver 5 to MX-4 between my new i7-4790K and my NH-14D. In short, I ran mprime (Linux64,Prime95,V28.5,build 2) using large FFTs with 8 threads and logged the temps throughout the run once per second using a shell script. Ambient temp which is very important to consider did not vary more than 2 F since the system was placed in my basement where it is very consistent. The digital thermometer showed 59F as the low and 61F as the high which is approx 1 C.

Run 1 was Arctic Silver 5 which had cured for approx 52 hours. I ran mprime as noted above for 4 hours.
Run 2 was with MX-4. I ran mprime as noted above for approx 1-1/2 hours.

Histograms in blue show the temperature distributions for AS5 and those in pink show the same for MX-4. The solid black line for each core is the average temp for each core. You can clearly see differences between the two of 2-4 degrees (allow for +/-1 C due to the ambient temp range). AS5 was the superior TIM in the test experiment.

Test system
Processor: i7-4790K @ 4.40 GHz (vcore 1.232 volts under load)
HSF: NH-14D with 120mm and 80mm fan running at max
Motherboard: MSI Z97 MPOWER MAX AC

EDIT: I have to totally invalidate my findings based on a configuration oversight: it seems that $HOME/prime.txt on linux dictates what size FFT mprime uses. I have found that using "large FFTs" as I did the the experiment allows for values of 128k-1024k which is a range that causes a given CPU various levels of stress. The trend is for smaller values to give more stress and as a result, higher heat. In short, I have no way to go back and see which FFT size prime was using when I compared these two. Here are my findings using the same TIM, but varying the FFT size. Each run is a average of 20 min of running.



I have since locked the FFT size to 400k and will repeat this experiment.

Nice comparison

Good.

As I have a NH-D14 on it's way to me now
And I still have AS5

No multiple mount testing?
That slight difference could easily be a better/worse mount on one test.

ATMINSIDE said:

No multiple mount testing?
That slight difference could easily be a better/worse mount on one test.

Click to expand...

Good point here. That could easily be the reason for the curious results. In other more empirical testing mx4 matches or is slightly better than as5.

EarthDog said:

Good point here. That could easily be the reason for the curious results. In other more empirical testing mx4 matches or is slightly better than as5.

Click to expand...

Well I for one want to welcome our AS5 overlords.....

Agreed that mounting is a variable I didn't control for in this since only singlet data. I'm not going to do multiples on each TIM. Too time consuming.

Actually, according to this study, variability introduced as a function of mounting technique can be ignored in my opinion so long as moderate to great contact is achieved. They showed that variance of <1 degree C can be achieved, so I think these data and the conclusion stands as valid.

graysky said:

Actually, according to this study, variability introduced as a function of mounting technique can be ignored in my opinion so long as moderate to great contact is achieved. They showed that variance of <1 degree C can be achieved, so I think these data and the conclusion stands as valid.

Click to expand...

They're also using a water block with a custom mounting method so they can control the mounting pressure very precisely.

You're using an air cooler.

Consider the results I presented invalid. I did not control for the FFT size (thought I did but later realized the defaults define a range). I edited the first post of this thread and will repeat.