One feature that Intel has had for some time is the ability to change the personality of its Xeon CPUs dynamically. On CPUs that have “Y” suffixes, and with compatible servers, we can get access to Intel Speed Select Technology or SST. This allows us to change the core counts, frequencies, and TDP of CPUs to different levels easily. We are going to show how to change the personality of a Y series Xeon using a Dell PowerEdge R760 iDRAC 9 interface since it is very easy.
How To Change Core Count and TDP of Intel Xeon Y CPUs on Dell PowerEdge
The two main components of making this capability work are having a compatible CPU and server. Here we have the Intel Xeon Platinum 8452Y as you can see here.
When these are installed, changing personalities is fairly straightforward. One can use BIOS, or even just the iDRAC 9 BIOS setting page. Here is the dropdown SST-Performance Profile:
Here we can see the options:
- Operating Point 1: P1: 2.0 GHz, TDP: 300w, Core Count:36
- Operating Point 2: P1: 1.9 GHz, TDP: 270w, Core Count:32
- Operating Point 3: P1: 2.1 GHz, TDP: 250w, Core Count:24
These match the Intel Ark page Intel SST-PP:
That BIOS setting can be selected, then the server reboots and the new performance profile will take effect.
Using Intel SST-PP is extremely easy. Most STH readers with SST-PP enabled Xeons are probably using the default maximum core count profile. Still, this is an option and is very easy to change. If you are wondering what the use case is for moving to lower core counts, that is fairly easy.
We saw a good example of how this is used recently in our Putting the Bare Metal Server in the PhoenixNAP Bare Metal Cloud piece. There, PhoenixNAP uses Supermicro servers with the same Intel Xeon Platinum 8452Y SKUs. Having Intel SST-PP options allows for one SKU to be installed then multiple types of bare metal instances to be serviced from that one SKU.