Ubuntu Vs win7

Any chance at all on an hp dm1z I'll get the same bat life as in win7?

 

unlikely. Windows power management is much more advanced.

linux has caught up a lot but still way behind.

 

It'll depend on driver support, and I believe Fusion has some problems in Linux driver-wise. Historically, out-of-the-box, the same machine running Linux usually had worse battery life. Not entirely certain, as I haven't tested. But, it is possible to undervolt the E-350 in Ubuntu just the same as it is possible to in Windows (see link in my signature for my X120e, which shares the same internals).

 

the key issue of linux power management is that many programs(daemons or whatever it is called now) still use the 'poll' model which doesn't play nice with Intel's speedstep. That prompt Intel to make this

LessWatts.org - Saving Power on Intel systems with Linux

Haven't follow them too closely nowadays so not sure how good they are.

 

Fewt or Fuduntu, a long-time member of the eee user and ubuntu forums has worked on aurora and, more recently, developed his own spin on Fedora called Fuduntu. He's ported and transformed the old eee applet from cruncheee and eeebuntu into a broader power management applet called jupiter. Jupiter obviously works in fedora but it seems like you could probably get it working in ubuntu.

Jupiter Applet

 

I'm dual-booting Windows 7 Home Premium x64 with Kubuntu 11.04 x6 on an HP ProBook 4430s.. I also have QuickWeb enabled. Batery life in Win 7 is very good, up to 4hrs depending on use. In QuickWeb, I can get close to 5hrs if I'm careful with what I'm doing. Right now, I get about 3-4hrs in Kubuntu with the KDE settings and Jupiter. On the downside, it makes text entry in Opera a little slow =(

EDIT: It looks like the slowness of text entry in the quickreply box in Opera was caused by disabling desktop effects. I went through and turned off most of the eye candy (which I really don't like anyway), kept a few niceties, and re-enabled desktop effects under my power-saving plans. Text entry is normal, and the battery monitor is currently reporting 4hrs, 6min.

 

Battery life will probably bit a bit better under Windows, but Linux has caught up *tremendously*. It's much, much better now than it was even just a couple years ago, and a lot of the perception of "Linux has horrible power management" is based on long-outdated information.

That said, it's likely that you'll have to spend a couple minutes doing some tweaking for your specific model. (Windows needs that sort of tweaking too, but the manufacturers tend to do it for you.)

 

My battery life dropped dramatically on my netbook when I put Ubuntu on it.

But it still gets a good 3 hours or so. Which is just fine. Especially since Ubuntu generally runs faster on this machine.

I'm hoping Ubuntu 11.10 will help improve things even more.

 

Also since Kernel 2.6.38 and newer their is a Power Management issue in the Kernel. It has to do with PCI slots, I believe their is a fix for it mentioned on the forums, but I am to lazy to find it.

Google search 2.6.38 kernel battery life bug, or something.

 

Except for the latest 2.6.38 regression the general problem with power management under Linux is that virtually no BIOS really works the way it should according to the specs. They are all full of bugs and evil hacks to circumvent them which in turn creates new bugs and... it's a never-ending story.
While the manufacturers happily provide Windows drivers that address all this mess the Open Source scene usually has to reverse engineer all these bugs one by one.
The logical conclusion would just be to stick to the specs when implementing a new BIOS but I guess "someone" isn't interested in working standards.

 

It's actually a power management issue with various BIOSes, not with the kernel.

Also, the impact is minimal. Phoronix made a big stink about it, but actual user reports are that the savings are tiny at best.

See above: it takes a bit of tweaking, since unlike the vendor pre-loads, a generic install of an OS isn't going to be optimized for your hardware.

 

I've gone through the lesswatts site several times and found and many of the tweaks in the Tips & Tricks area were eventually implemented into the kernels or daemons and aren't necessary (I'm on 2.6.35) and others (HAL if I remember right) is not included in newer kernels so it was irrelevant. Powertop I've personally found to be useless other than giving a register of the wattage being used on DC power which seemed to be accurate when checking against HardInfo and Batterybar in Windows.

The only things Powertop would want to do for me would be disabling the optical drive, hd audio and turning down range of the wifi card. The optical drive never actually stayed off and whenever I would set anything in Powertop, my draw would go from 1.9w to 2.1w. I've not used it for a few months and development also seems to have stopped a while back.

Keep in mind too that not all distros install with CPU scaling set correctly and if that's not right it'll destroy battery life. I've had several instances where I've had to manually set the power scaling daemon and governor and for Ubuntu based distros, actually set the cpufreq config files to switch them from processor states of min 100%/max 100% to min 0 and max 100. I'd also have to set the governors for each power state (AC, DC, low DC, etc.).

I don't know why they installed that way but until it was fixed, the CPU would sit at its highest clockspeed in the performance governor regardless of the running applications. Once fixed, battery life improved significantly. With a Core 2 Duo, I'm probably about 20 minutes off what Vista was giving me. Well worthwhile to be unhooked from the Windows wagon.