CPU power consumption differences between BOINC projects

Two weeks ago, when I changed my BOINC project from Universe@home to Rosetta@home, I noticed that my laptop was getting much warmer where the heatsink is located.

I understand that BOINC projects are built in different ways using a variety of programming languages with their individual optimisations. The memory footprint and utilisation varies and some require more HDD access than others. So, although a system may report 100% CPU utilisation, it doesn’t mean the CPU consumes the same amount of power or generates the same amount of heat for each project.

To better understand this, I decided to test the effects of CPU heat generation and power consumption on my laptop for each of the whitelisted Gridcoin BOINC projects.

The conditions:

Hardware/external:-

• Laptop with i5-6200U and 8GB memory
• Fanspeed fixed at 3000RPM
• Room temperature 23 degrees Celsius

Software:-

• Windows 10 (x64)
• BOINC 7.6.33 (x64)
• Stopped all other programs that consume CPU cycles (virus scanner, internet browser etc)
• Use Core Temp 1.10.2 to measure the CPU temperature and power consumption

Test setup:

• Select only projects with CPU tasks (so no GPU or Vbox/WM tasks)
• Run one project at a time on 4 threads
• Ensure CPU load at 100%
• Run tasks for at least 5 minutes before measuring the temperature and power consumption

And here are the results:

I was expecting to see some differences but it struck me how big the differences really are. Below a number of observations:

• There is a direct linear correlation between power consumption and CPU core temperature (not surprising)
• The difference between the top and bottom application is 14 degrees Celsius (20% difference). Of course, when I increase the fan-speed the temperature delta will be less but there will also be more noise (not ideal in my case).
• The difference in CPU power consumption between the highest and lowest consuming project is 4.2W (40% difference).

After running these tests, I finally understand why my laptop got much warmer while switching from Universe@home to Rosetta@home. The CPU started to consume 2.2W more which resulted in temperature increase of 7 degrees Celsius.

I have now installed the tool called TThrottle, which you can download for free at https://efmer.com/. It will automatically adjust the BOINC project(s) CPU utilisation not to exceed a maximum set CPU temperature. Of course my output has dropped a bit but my laptop doesn’t get too hot to handle anymore whilst I can still run my favourite projects.

I hope you found this article helpful and interesting. Keep on crunching your favourite project!