Undervolting - testing stability?

[Axium]

So I use setcpu to lower the voltage of my slots but what's generally the best way to test every slot out? With the stress test option or is there another app?

Sent from my Galaxy Nexus using DroidForums

 

[bhfd64]

So I use setcpu to lower the voltage of my slots but what's generally the best way to test every slot out? With the stress test option or is there another app?

Sent from my Galaxy Nexus using DroidForums

I've never used an app to monitor any kernel configuration. If the phone stays awake and doesn't get too hot then it's good enough for me.

 

[Axium]

have you ever tried to undervolt? not talking about overclocking or whatnot.

 

[orion2001]

Axium, I used a combo of SetCPU stress test and Antutu Benchmark. However, I should mention that despite being stable with both of those, I did have my phone reboot a couple of times, so I raised my voltage @350MHz by 25mV and the phone has been stable since.

My suggestion is to go about the undervolting really slow. Start with the 350MHz slot (most gains to be had there as the phone is usually at 350MHz when awake and not being actively used). Also, some of the devs have mentioned that being too aggressive when undervolting can lead to extra battery consumption because the phone might get too sluggish and have issues with going into deep sleep properly. I used Antutu benchmark to make sure that the scores didn't drop when undervolting (although the numbers are not the most repeatable).

Once you settle on a voltage setting, I'd use the phone for a day or two. Try doing lots of multi-tasking and processor intensive stuff and see if it reboots or is stable. Once you're happy with 350MHz, you can repeat the same process for the higher frequencies.

 

[cupfulloflol]

A few things to note:
- Never set anything to set at boot until you are 100% sure it is stable.
- Test one speed at a time.
- Nandroid backups can't hurt.

Onto my testing methods, which aren't too different from orion2001's.

Starting with stock voltages, I go into SetCPU and set the min and max to the same speed (locking it into that speed). I then perform a benchmark for each speed. Antutu or CFBench will work, but they will take a while if you are testing the lower speeds. You may want to run the benches a few times to see what you will be looking at (scores fluctuate a bit between tests). I do this to get a control and so I know what each speed should look like. I write these scores down for each speed.

I then start undervolting on slot at a time. I like to start with the lowest slot, as it is where my phone spends the majority of it's time. I change by 25mV at a time. Using SetCPU I then lock my processor into that speed. I then run the benchmark a few times. I compare scores, making sure they are in a similar ballpark. I do that for every slot.

After I am satisfied with my voltages, I then use my phone as normal (not set on boot still). I look for odd things to happen. Slowdowns, random reboots, problems with apps, inexplicable battery drain, phone getting hotter than normal, are all potential problems of undervolting that may not crop up during tests.