[G2 Q&A, Help & Troubleshooting] bloof:
COMPARISONS

2 CORES HIGH FREQUENCY (2.88 GHz)

VS

4 CORES LOW FREQUENCY (1.5 GHz)​

Similar Performance, Lower Power Consumption​

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SETUP:

Running the great app trepn from qualcomm to monitor power and core frequencies.

For each case:

1. Monitor System with trepn

2. Launch PCMark and run "Work Benchmark"

3. When done, go to Vellamo and run "Multicore" benchmark

4. When done, end System Monitoring with trepn

5. Also for each case run a baseline power consumption (trepn does consume a lot of power): run system monitor and do nothing on the phone. This enables taking out trepn for comparison.

Caveat: I didn't have time to run these in perfect controlled manner. Some heating issues could have come in, some extracurricular apps been launched in the meantime, and some timing issues since I did this by hand.

However, I did wait about 2 hours between runs, and the tests being about 10 minutes removes some of the timing issues.

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Case 1 - 2 Cores at High Frequency:

Setup:

- OnePlus One running Boeffla kernel

- Intelliactive governor

- CPU max frequency: 2.8 GHz

- GPU max frequency: 462 MHz

- Hotplug: "2 cores exact" this also means that cores do NOT go to idle when done with their tasks

Results:

The first graph below show the frequencies for each core during the entire test. As expected 2 cores are never switched on. The other 2 follow the exact same scaling and load (pretty much).

The Second graph shows TOTAL frequency on the left with time (I just added them up) and power on the right as well as cumulative power.

TOTALS:

- Time: 584 seconds

- Power: 14.24748 (approximate assumption that each data point happens at regular interval, makes life easier)

- Clock Frequencies: 20,001,424,800 (approximate assumption that each data point happens at regular interval, makes life easier)

TOTALS for baseline:

- Time: 316 seconds

- Power: 4.202236(approximate assumption that each data point happens at regular interval, makes life easier)

- Clock Frequencies: 5,183,685,600 (approximate assumption that each data point happens at regular interval, makes life easier)

- Power to subtract for 584 seconds of trepn: 7.766

- Clock Frequencies to subtract for 584 seconds of trepn: 9,579,975,919

- Baseline power consumption per clock: 0.81

- Baseline power consumption per second: 0.0133

=> TOTAL NET POWER CONSUMPTION: 6.48

=> TOTAL NET CLOCK CYCLES: 10.4

=> POWER per clock cycle: 0.623

FULL RUN:

BASELINE:

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Case 2 - 4 Cores at Low Frequency:

Setup:

- OnePlus One running Boeffla kernel

- Intelliactive governor

- CPU max frequency: 1.497 GHz

- GPU max frequency: 462 MHz

- Hotplug: "4 cores min" this also means that cores do NOT go to idle when done with their tasks

Results:

The first graph below show the frequencies for each core during the entire test. As expected 4 cores are always online, no idle core.

core1 seems to have a weird result of going up to 2.5 GHz. Not sure what happened there. graphs from PCMARK and Vellamo do NOT show this.

The Second graph shows TOTAL frequency on the left with time (I just added them up) and power on the right as well as cumulative power.

TOTALS:

- Time: 624 seconds

- Power: 12.45498 (approximate assumption that each data point happens at regular interval, makes life easier)

- Clock Frequencies: 23,214,439,200 (approximate assumption that each data point happens at regular interval, makes life easier)

TOTALS for baseline:

- Time: 311 seconds

- Power: 3.90047 (approximate assumption that each data point happens at regular interval, makes life easier)

- Clock Frequencies: 7,385,724,000 (approximate assumption that each data point happens at regular interval, makes life easier)

- Power to subtract for 624 seconds of trepn: 7.826

- Clock Frequencies to subtract for 624 seconds of trepn: 14,818,944,617

- Baseline power consumption per clock: 0.53

- Baseline power consumption per second: 0.01254

=> TOTAL NET POWER CONSUMPTION: 4.629

=> TOTAL NET CLOCK CYCLES: 8.39

=> POWER per clock cycle: 0.552

FULL RUN:

BASELINE:

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Conclusions:

Baselines:

- Difficult to compare since anything could have been happening to the phone while this was carried out (emails, syncing, etc).

- However, 2 cores at 2.8 GHz show higher consumption. Since is true: 2 cores were idle at 0 whereas the 4 cores baseline had all cores switched ON. Allowing cores to go back to idle would have favoured the 4 cores case and the difference in power consumed would have been greater.

- I could remove all 300 MHz frequencies and redo everything but I won't, don't have time.

Power consumption:

- I will assume that each run performed the exact same tasks.

- Without removing baselines, the 4 cores at low frequency consumed 13% less power

- Removing baselines, the 4 cores at low frequency consumed 30% less power

- However, the 4 cores at low frequency took 7% longer to achieve the task

It would be great if some of you could test this in your own setups for daily life! And let me know how it goes.