Does Jupiter really improve battery power?

In OMGUbuntu, WebUpd8 and I think Phoronix they have an article about how it helps with the power management. Also several users have actually reported saving battery time. This of course changes depending on the hardware and the usage. For example, setting the mode to Power Saver while playing an intensive game or doing something process/power hungry will eventually eat the battery.

Some links about this are:
http://www.webupd8.org/2010/07/jupiter-ubuntu-ppa-hardware-and-power.html
http://www.webupd8.org/2010/06/jupiter-take-advantage-of-asus-super.html http://www.omgubuntu.co.uk/2010/02/jupiter-awesome-netbook-powerconfig-applet/
http://eeepc.net/jupiter-adds-power-management-to-linux-netbooks/

But some suggestion would be to read the comments in each of this links, check the Jupiter site here: http://www.jupiterapplet.org/ for updates and support. Jupiter might help many laptops, netbooks and small eee but might not do much to others depending on the way they handle the power management. Most users actually have good reviews.

Lastly there are some improvements in the last days in the source: http://sourceforge.net/projects/jupiter/

which at least suggests it is still active and work is getting to it.

Here is the link to an article writteb by the creator of Jupiter.

The myth of linux kernel regression

I have to say one thing, I do not know how it works and the only feature that I know is advertized by all is "saves battery" but I have installed it on my desktop (to answer another question) and forgot about it.

It was still running with max battery when I was playing games on wine and I have noticed that the game frame rate was very low (really really low), I troubleshooted the only possible cause as being jupiter and moved the profile to max performace, frame rate jumped without any reboots or something.

So, yeah, I know this is not definitive proof but I will say it is somehow managing your CPU / GPU settings enough to get you some power saving. How much I cannot tell without measuring power consumption at the PSU, but it is doing something.

In my experience, it works if you are utilising your CPU, but if you are like me, and just trying to stretch extra time out of note-taking with the backlight on low, then no it's not going to help. Alvar and Bruno are right, it limits your CPU and GPU to a certain multiplier cap, which is great if you are trying to get extra battery life from reasonable intensity usage, but again, won't help in bare minimum situations (text editing, writing).

jupiter limits the amount of performance you van get out of your cpu/gpu. Does it help? Well Jupiter uses some power to work, but it does limit your performance. So really the only way you can save even more power is to dim the display, spin down the hard drive when possible.

But also if you want to get more battery life, don't use so heavy programs.

You should also look in power management.