Why an Overclockable Core i3 Might Not Exist: The Supermicro C7H170-M and Intel Core i3-6100TE Review

Base Clock Overclocking the Core i3-6100TE: Scaling

As mentioned at several points in this overall piece, overclocking using the Supermicro C7H170-M was actually really easy. There is a single option in the BIOS under ‘Extra Performance’ where you can change the base frequency from 100 MHz to 150 MHz in 5 MHz increments. This doesn’t adjust the processor voltage, and we have no load line calibrations, but that didn’t seem to matter much.

There is an option for Core Voltage Offset, although I’m not so much a fan of offsets when I saw a motherboard a couple of years ago apply a double offset, and I freaked out in case it burned out that $999 CPU. In this case though, we did not have much trouble.

Adjusting the base frequency will adjust the memory speed as well, so the two main limitations will be the processor itself (either physical limits, temperature or voltage) and the memory (also limits, temperature and voltage). This can become tricky to manage as a 35% overclock on DDR4-2133 memory can instantly push it to DDR4-2880. There is an option to reduce the memory multiplier if needed in the BIOS.

As for testing the limits of overclocking, we employed our regular methodology. Increase the frequency, run a pass of our POV-Ray benchmark followed by five minutes of OCCT, noting the voltage, temperature and power where possible. If it passes these two tests, we reboot into the BIOS and increase the frequency. If we fail the test, we would typically go back and reduce the voltage, however this wasn’t needed here. Our results are as follows:

In this case our CPU worked well all through our tests until 145 MHz, or 3.915 GHz for the processor that starts as a 2.7 GHz part. Here when we applied a strong load, it caused the system to blue screen. We tried with other benchmarks, and confirmed that the system was sort of stable, except for gaming and video editing. So as a result we moved back down the scale and found 135 MHz a reasonable compromise for the testing for the full benchmark suite.

But for testing the scaling of the overclock we did our short form benchmark suite on 100, 130, 135 and 140 MHz do see if performance in these benchmarks can accurately scale. As one of the bigger questions, we of course also did some gaming benchmark testing, using our GTX 980 at each of the points. For users interested in R9 285, R9 290 and GTX 770 data at 135 MHz, please look at our benchmark database.

Testing the Scaling – CPU Short Form

In all of our short form tests, the scaling from 2.7 GHz to 3.78 GHz was near perfect, particularly in 3DPM single threaded. The more you put in, the proportional you get out.

Testing the Scaling – CPU Extra

We also had some extra testing on hand. A few benchmarks showed an odd jump between 135 MHz and 140 MHz, such as Agisoft and Cinebench 10 single thread. Dolphin saw some odd regression at 140 MHz, but the general trend still stood.

Testing the Scaling – GTX 980 Gaming

In our gaming tests, every title showed proportional gains such that moving from 130 to 135 MHz did the same increase as moving from 135 to 140 MHz, although in some cases it was really, really minor. The best way to look at it is to plot a graph of frame rate against CPU frequency, and find where the frequency = 0 cuts the line and note the gradient. What matters here is two points. If the intercept (frequency = 0) value is high, then it offers a good performance no matter what. If the gradient is high, then you get a better response per adjustment in frequency.

From these results, essentially everything except Mordor seems to get really nice gains (proportionally) from increasing the frequency.

As an exercise in stupid numbers, here’s a calculation. Using the intercept and gradient, and assuming a perpetual linear relationship, calculate the frequency needed for 60, 120 or 240 FPS average. The results are:

Because of the titles that scale, I’m inclined to believe some of these numbers, such as Alien Isolation and GRID, but Mordor is just amusing as the minimum scales faster than the average in our small test. Give me a ring if we ever hit 70 GHz.

A Word on Power Consumption

It turns out that power consumption numbers becomes a byline in this test. At stock frequencies and at +35% overclock, the power consumption of this 35W part moved from 32W to 38W, which is pretty much what was to be expected.