Reasons to use adaptive and energy saving power plans

Question

This is Question and Answer topic.

After many years of using laptops, desktops and servers I asked myself - why adaptive and energy saving plans exist in desktop and server computers? Why would I use energy saving when laptop is not running on battery? why I'm always using "Maximum performance" power plans? Who cares about "few watts" of power that can be saved?

So the main question is:

What are advantages of adaptive or energy saving power plans?

Answer 1

1. Energy saving.

Well, some people have habit to turn on "Maximum performance" profile on every computer they use. No matter if you are average, rich or poor - you can save money.

I have energy meter. My old laptop with Core 2 Duo (35W TDP) and Nvidia Quadro GPU (10W TDP) consumes energy worth about 6$/month when I'm using "Maximum performance".

On "Adaptive" - it uses 4$/month. I see no difference in performance and I can have free beer every month :) If I had desktop with 70-90W CPU and 60-70W graphics card - I probably could save 5$/month or more and buy pizza :)

2. Reducing generated heat

CPU and GPU generate heat. Heat amount depends on CPU voltage. When CPU is running on maximum frequency - it uses "normal" voltage. When you use Speed Step on Intel CPU and reduce frequency - CPU can work stable at lower voltage. Lower voltage means less heat.

3. Fans wear out faster

But what if you don't care about heat? You may not care, but when you have maximum performance profile - your fans on CPU and GPU have definetly more work. Bearings wear out faster when they work at faster speeds and higher temperatures.

4. Cooling system becomes dirty faster

When fans work at higher speeds - dust settles on radiators faster. If you have no air conditioning with air filters - after year or more - your radiator may be really dirty.

5. Laptop battery wears out suprisingly fast

...if you use maximum performance on battery. If you need to work on battery for only 30 minutes and your battery can run 1h on maximum performance - use energy saving anyway, especially on fast laptops. Reducing discharge current can double your battery life. I mean battery wear out, not discharge time.

So, if you always turn on "Maximum performance" on your computer - just try to use "adaptive" or "automatic" power plan and see if you have any performance problems. If not - you can extend your computer life or at least extend time between failures :)