The system is Minisforum MS-01 mini PC. I have installed 96GB Crucial DDR5 5600 RAM and Samsung 4TB 990 Pro SSD. OS is Ubuntu 24.04.
I9-13900H has 6 performance cores with up to 5.4GHz freqency and 8 efficient cores with up to 4.1GHz frequency. Additionally the performance cores can be configured in BIOS to enable hyperthreading (SMT), which essentially doubles the CPU core count for P-cores. When SMT is enabled, the total number of CPU cores is 20 from OS perspective.
Ubuntu supports 3 power mode: performance, balanced and power saver.
| power mode | performance | balanced | power saver |
| observed cpu freq. | P-core: 5400MHz E-core: 4100MHz | 3800MHz | 2500MHz |
| SMT enabled | single: 2713 multi: 13571 | single: 1968 multi: 11484 | single: 1147 multi: 3436 |
| SMT disabled | single: 2657 multi: 13393 | single: 1970 multi: 10647 | single: 1141 multi: 3131 |
A few observations:
- SMT does not change single core performance (expected) and add a little (2%-10%) to multi-core performance.
- Multi-processor scaling is not very efficient, because multi-core score is usually about 3x-5x of single core score, while there are 6 performance core and 8 efficient cores in the system.
- Ubuntu achieve various power modes by capping maximum CPU frequencies.