Looking at the Intel Ark specifications, I see that Emerald Rapids has a new feature that has not been mentioned.
For all models at which I have looked, it is possible to split the cores into a smaller group of cores running at a base frequency that is higher than the nominal base frequency and a bigger group of cores running at a base frequency that is lower than the nominal base frequency.
For instance, for a model with 28 cores at 2.1 GHz base frequency it is possible to split them thus:
- High Priority Cores 8
- High Priority Core Frequency 2.3 GHz
- Low Priority Cores 20
- Low Priority Core Frequency 1.9 GHz
As another example, for a model with 64 cores at 1.9 GHz base frequency it is possible to split them thus:
- High Priority Cores 20
- High Priority Core Frequency 2.1 GHz
- Low Priority Cores 44
- Low Priority Core Frequency 1.7 GHz
I wonder how exactly can this be done. I hope that Intel will publish a specification, or at least they will provide a Linux driver.
@Patrick: Have you tested this feature? If not, I believe that you should (but I suppose that first Intel must provide some kind of configuration tool).
EDIT:
Looking again at Ark, I see that I was wrong and this is not a new feature, but it has already been introduced since Ice Lake Server. Even if this may be in part due to the fact that in recent years I have paid little attention to the Intel server products, because they have been almost always non-competitive, I do not remember to have ever seen a test using this feature of core partitioning. I still believe that this would be an interesting test to perform.
