Intel seems determined to make a mark with Alder Lake. Not only in terms of performance but also in terms of power consumption. According to research by German friend Igor, the BIOSes of upcoming Z690 motherboards will have an option to set PL1 values equal to PL2.
This essentially means that the power consumption of Alder Lake chips will be twice as high as their predecessors. Setting PL1 the same as PL2 makes a big difference to the raw performance of a CPU. First, it skews the performance benchmarks because you are essentially comparing two products with very different power consumption and efficiency. But we know that raw performance often obscures its consumption.
An option present in the BIOS?
And this is obviously the most egregious, this setting is not conducive to energy efficiency . Chances are that this setting will appear in some BIOSes as a “Boost for gaming” option. Enabling this option will therefore give rise to several interpretations for those who have to test it. It seems obvious that everyone will be looking for maximum performance in the tests. With Rocket Lake-S you could already set PL1 to the same level as PL2 from the BIOS settings, but this was not enabled by default. We’ll have to watch the situation on the Z690 bios in the next few hours.
Nevertheless, if this information can make you sweat, we can still see (thanks to Rocket Lake in particular) that Intel knows how to manage its power consumption peaks and the related dissipation. Intel ensures that its partners associate Z690 motherboards with voltage regulators capable of avoiding any “incident”.
Protocols in place:
Validating electrical and thermal capabilities
It is recommended that system integrators verify with PL1=PL2 settings and that the listed specifications do not have a negative thermal impact on the VR or CPU. This can be done by running: – Five consecutive iterations of CineBench20 (MT). 5-10 seconds between runs. – Verify that the scores are within the distribution (+/- ) 2%. – No VR thermal events.
Thermal capacities of the SoC heatsink
– End-of-life thermal solution performance requirement shall be 0.07°C/Watt – The system state assumptions for these requirements are as follows: – TjMax = 100˚C – Local ambient= 30˚C – Alder Lake S 8+8+1 125 W SoC
VR Thermal Additional Recommendations – For designs with 8-phase VR, which configure PL1=PL2, passive heat sinks are recommended on VR components to avoid VRHOT# assertion. – In addition, Intel recommends that board manufacturers perform thermal testing of VR components under the above load conditions to assess the need for passive cooling on their specific topologies.
- IA Iccmax (A) 280
- IA IPL2 (A) 184
- IA i (A) 208
- IA t (ns) 200
- IA CC/CA LL (mΩ) 1.1
- GT Iccmax (A) 30
- GT IPL2 (A) 22
- GT i (A) 21
- GT t (ns) 250
- GT CC/CA LL (mΩ) 4.0
- AUX Iccmax (A) 28.5
- AUX DC LL (mΩ) 2.0
- PL1 (W) 241
- PL2 (W) 241
- PL4 (W) 359
These tests are essential for manufacturers because obviously sticking PL1 at 241 watts instead of 125 is bound to affect the reliability of motherboards (especially VRMs).
