VID tables and OC comparison
As already noted, the VID table of each CPU and the SP values calculated from it only tell part of the story about the silicon quality. To illustrate this, the VID table of a K and a KF CPU is compared side by side in the following long chart, where the 8 highest multipliers are listed in groups and in them the 8 P cores with their VID. I deliberately chose two CPUs with almost identical P-core SP values here.
Apart from the different start and end frequencies of the tables, it is noticeable that the VID values of the K and KS CPUs are almost identical at the overlapping frequency points, or the K CPU with 1 point higher SP value even often has the slightly lower values. If we now overclock the two CPUs, they should behave almost identically, perhaps with a slight advantage for the K CPU, since it has more voltage reserves.
Subjunctive intended, because in reality the picture looks quite different. I use Cinebench R23 to test the overclocking potential. And yes, even if the software is neither a reliable benchmark nor a meaningful stability test, it is good as a quick OC test and indicator for the silicon quality.
To run 5.3 GHz on all P cores and 5.0 GHz on the cache in Cinebench, the 12900K needs a voltage under load of 1.314 V Die Sense, for which 1.41 V must be set with LLC Level 6 in the BIOS or TurboV Core.
However, the 12900KS with theoretically slightly inferior P-cores only needs 1.190 V under load for the same clock rates, with 1.275 V as the target value with an identical LLC. Even if the KS CPU runs a bit cooler because of this and a few millivolts of savings can probably be attributed to it, the difference between the CPUs amounts to an incredible 124 mV. Even with other CPU pairings with almost identical SP values, the KS CPU always wins significantly with 100 – 150 mV less voltage for the same clock. This is exactly the reason why comparing the CPU types based on the SP metric alone is only of limited use.
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