A massive effort to test and sort Intel Raptor Lake CPUs by overclocking capability has yielded some surprising results: Igor's Labs, in cooperation with MIFCOM, has tested over 500 of Intel's latest (open in new tab) 13th generation processors to determine whether they have overclocking potential or not. They looked to see if they were predisposed to overclocking or if they were silicon deficient. The data led us to the surprising conclusion that the Core i9 13900KF is the best overclocker of this generation. It even outclasses the more expensive Core i9 13900K (open in new tab).

The incredibly complex lithographic process of etching very complex designs onto silicon is very accurate today, but still not perfect. Slight differences between individual dies can cause one CPU to outperform another CPU when overclocked. In short, one CPU is better than another.

To be sure, the days of a near-perfect CPU running hundreds or thousands of megahertz faster than another CPU of the same model are long gone. But there are still so-called "golden samples," CPUs that are better suited for overclocking than others. Whether you can get your hands on it depends largely on the luck of the draw, but according to a report by Igor's Lab (via Tom's Hardware (opens in new tab)), it is possible to turn the odds in your favor.

The first test results posted here compare the Core i9 13900K to the Core i9 13900KF. The results compare these two chips using the proprietary Silicon Prediction (SP) feature on Asus motherboards. This is essentially an assessment of the overclocking potential of any given chip based on the factory-set voltage curve for each CPU

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The higher the SP value, the higher the overclocking potential of the chip.

The results of the large batch tests were quite surprising: the Core i9 13900KF without an iGPU generally had higher SP values (sum of both P and E core values) than the more expensive Core i9 13900K, 101.1 vs. 99.6, respectively

This is not the result I was expecting, but it makes sense why it would be. Intel sorts its CPUs so that the best die goes on the most expensive chip, but perhaps what we are seeing here is the result of removing the iGPU from the equation.

Take, for example, this Raptor Lake CPU die fresh off the wafer at Intel's fab facility in Israel (opens in new tab): the maximum Raptor Lake configuration is 8+16 (P-cores and E-cores), which means that only fully functional dies will be used in the Core i9 13900K. This means that only fully functional dies will be included in the Core i9 13900K. If some of the E-cores are non-functioning dies, that would make it a Core i7 or lower processor; if some of the P-cores are non-functioning, it is likely to be a Core i5 or lower. If all are working properly, it is likely to be a Core i9.

However, for the Core i9 13900K, Intel must have a fully functional iGPU. If this does not work as intended, this die will end up in a Core i9 13900KF; even if the CPU component is great, if the GPU does not work, it will be a Core i9 13900KF.

Another thing to consider is that the absolute best Raptor Lake die, the one where all cores work and the GPU works, will be used not only in the Core i9 13900K but also in the recently released Core i9 13900KS (open in new tab). The Core i9 13900KS was just released last week, so the results do not reflect this, but in effect, the Core i9 13900KS is composed of the best die from the Raptor Lake production line.

Essentially, Intel is extracting the best die from the top of the Core i9 13900K stack for the Core i9 13900KS. They will pay an additional $100 for this binning process.

This may explain the higher SP score of the Core i9 13900KF and the higher overclocking potential; the Core i9 13900KF is the end point for some CPU dies while the Core i9 13900K is not.

In the second wave of results (opens in a new tab), Igor's Lab compares the Core i7 13700K with the Core i7 13700KF and the Core i5 13600K with the Core i5 13600KF.

And again, there is much to talk about.

For starters, the average SP value of the Core i7 13700K is 82.9, which is actually lower than the Core i7 13700KF's 83.5. However, the data for the K-series chips show a much wider range of performance, with values above and below the average. A handful of chips show values above 90, while many are below 80.

The Core i7 13700KF is far more likely to have a middling SP value. Not a single chip tested had an SP value above 90, and by far the most common was 86. There were also a small number of chips with low scores.

Even more interesting is the comparison between the Core i5 13600K (in our opinion, the best gaming CPU (open in new tab)) and the Core i5 13600KF. the Core i5 13600K had a higher average SP value of 81.8 and less variation in score between chips. the Core i 5 13600KF has an average SP value of 78.5; however, some of the golden samples had individual SP values much higher than the best Core i5 13600K sample, and some had much lower scores.

Overclocking does not have as great an impact on real-world performance as it once did, and it is unlikely that a few points of SP value will improve PC performance. However, for the avid hobbyist overclocker, it is seldom that so much data is available. Which CPUs have the best chance of winning the so-called silicon lottery is often based on anecdotal reports from other overclockers. Getting this much data, which more or less shows the best way to win the silicon lottery, is a great opportunity to get a glimpse of how Intel's binning process works and selects processor dies for a generation.