Just thought I'd put my input into this topic.

I tested my phone for a 20min period, twice before the Smart Reflex change, and twice after if (leaving my phone idle for 30 mins or so before testing after bootup)

Pre-hack:
1) 11mAh after 20 mins
2) 14mAh after 20 mins

Post-hack:
1) 12 mAh after 20 mins
2) 14 mAh after 20 mins

So for me at least, it doesn't seem to make a difference on idle. Whether it will or not during use remains to be seen. Although I didn't do any timed tests, I noticed the phone was less responsive and a bit slower to react. However, this could be because I read about other people's reports, so I had expected this to happen (I forget the name of the effect).

i have 125-825MHz OC kernel with smartreflex enabled without any problems. the battery holds for about 24hours average use when using wifi switcher to disable wlan. Used to get 12 hours max with light usage so this is no placebo.

Anyone successfully enabled smartreflex with undervoltage kernels?

It seems that TI has revamped some SmartReflex related stuff with recent kernel patches: http://www.mail-archive.com/linux-om.../msg26629.html

Smartreflex does not improve idle time. It's on the specification even!

What it does improve is use cases where the CPU is constantly not idle but not very busy either -- music playing, etc.

A 2x improvement with average use is not real.

Interesting.

Still, it seems to me that it does improve standby time by about one third.

And also, the N900 only freezes with SmartReflex enabled when its processor runs on max for some time.

Nokia has completely disabled SmartReflex in the PR1.2 kernel.
If you try to enable it, it ignores it with the warning "VDD2 smartreflex is broken".

Fixes: NB#160765 - remove sysfs interface that allows user to enable Smartleflex

/sys/power/sr_vdd1_autocomp can still be set to 1, but I wonder if it has any effect...

I tried only vdd1 and i think this only is a very big advantage.
I don't have numbers, but just for webbrowsing, idling, checking email and doing light stuff.
I think my battery life doubled

Vdd2 is unstable for me, after 1 night restart :/.

I downed the voltages also 1 jump, so 600 is on 54 and 550 on 48 and so on.

Let's see if this settings are stable for me for 1 hole day.

edit:

Normal on work i have 4 hours operation time, so fully using it, internet, little bit angry birds hihi.
Yesterday i could easy make 8 hours round and on home i still had battery, 1 hour driving with fm transmitter on, but home it was like 4mah hihi


Smartreflex > undervolting
I whatever case it's winning for me.
Only under full load undervolting is better, and full load i almost never use, i have no emulators or whatsoever and the sometimes the movies i check er max 1 min.

I need long battery live becuase overclocking even with undervolting kill my battery in a few hours.
On 600mhz with only undervolting is also nice but still smartreflex kicks it.