How to extend your battery life with an m15x

I've read a lot of reviews that get about 2 hours while surfing the web....

Steve @ NBF : 136 minutes (2 hrs 16 min)
http://www.notebookforums.com/thread214509.html

Packer : 100 minutes (1 hr 40 min)
http://www.notebookforums.com/thread212084.html

Chaz : 155 minutes (2 hrs 35 min)
http://www.notebookreview.com/default.asp?newsID=4328

So needless to say, I was a bit surprised when, after 2 hrs 30 min of class, I still had about 35% of my battery life left.


Here's my system with all important information...
Screen: WXGA 1440x900 LCD (glossy)
Processor: Intel(R) Core(TM)2 Duo CPU T9300 @ 2.50GHz
Graphics card: NVidia 8800m GTX 512mb
RAM: G.Skill 4GB PC5300 RAM (Vista recognizes about 3gb of it)
Bios Version: vX30 P3
Battery: 6 Cell, no smart bay battery
HD: Hitachi 200GB 7200RPM SATA
Wireless: Intel Pro Wireless 4965 a/b/g/draft-n
Intel Robson 1GB Pci-E Mini-card Turbo Cache Memory
OS: Vista Home Premium 32-bit

Here's what the m15x can do to minimize power...


Stealth Mode:

"System will not exceed 65w of power draw which will allow your system to operate in power limited environments." - m15x Users Manual

"The Area-51 m15x’s Stealth Mode throttles back the CPU and GPU, decreasing the notebook’s energy consumption and increasing battery life. Powering down the Area-51 m15x also reduces noise output. Higher energy efficiency and quieter running makes Stealth Mode especially beneficial when working unplugged and out in the field." - Alienware.com

It seems like Stealth Mode also turns ON fans when you first turn it on, but then it seems like all but one turns off after a moment and the system becomes quiet.

This is the easiest battery-saving technique to apply, simply press the button above your keyboard.

Also keep your computer well-ventilated and if possible, be in a cool area. A low ambient temperature in your room can mean your computer will have to turn on fans far less often... or never.

Turn down LCD brightness:

"Your LCD uses approximately 33 percent of your overall power usage. The size of your screen can affect power consumption—a larger screen requires more power. However, the single greatest LCD culprit is your backlight—a small, fluorescent tube. The brighter the screen, the harder that tube has to work. You can dim the screen/LCD brightness and choose a working environment with adequate lighting—less bright means you'll drain less power from your battery." - Intel.com

There's 8 levels of brightness, so use the lowest one that still allows you to see your screen. Readjusting the angle of your LCD can sometimes let you better see text or webpages without having to increase brightness.

Use Fn+F5 to turn down brightness or Fn+F4 to turn up brightness.

Set your power plan to "Power Saver":

AW's Fusion Optimization power management tool, or the Notification Area, allows you to change from "High Performance" to "Power Saver". This doesn't only change the time it takes your computer to auto-standby or power down the HDs, but it also actually reduces the maximum power your processor and certain parts of your chipset can draw.

You can do this by simply right-clicking the battery icon on your taskbar or going in to the Alienware Command Center.

Turn off AlienFX:

AlienFX refers to the light pipe on the outside of the LCD, the Alienware logo below the LCD, and the keyboard. The lights on the quick-touch buttons, the power button, and the alien head on the back of the LCD are not able to be turned off. Of course turning off unneeded lights will squeeze a little more power out of your system.

This is done by pressing Fn+F11.

Turn off/disconnect unnecessary peripherals:

This one's easy too. If you don't need bluetooth, touch the button next to the power button to turn it off. If you don't need wireless, touch the button next to the bluetooth button to turn it off. If you aren't planning on using your camera, turn it off by hitting Fn + F9. Unplug any USB devices you don't really need. These devices all use power even when not actively in use.

Taking optical discs out of the drive can also save batteries as when you open "my computer", the drive spins up to check what's on the disc.

If you want to surf the net and save power, try not to go to flash intensive sites and don't watch streaming media or download large files.

Change to the Intel GMA X3100 integrated graphics card:

The beauty of the m15x is that it's the only 15.4" laptop with Nvidia's 8800m GTX. Unfortunately, the 8800m GTX consumes 37 watts of power (assumed under full use). The m15x is also the only laptop that lets you switch between a full graphics card and integrated graphics. This may be the single greatest power saving technique along with one of the most obvious. It's also the most painful.

In order to switch to integrated graphics, or back to full graphics, hit Fn+F7 while the computer is on and you're logged in. You'll have to immediately restart your computer. How do you know you're in integrated graphics mode? Well you could try start a game. Or right click the desktop and look at the menu options. If it has a "NVIDIA Control Panel", you're still using the 8600-8800. If you get something else, it's the Intel GMA X3100. Also, if you're in Vista, you'll probably lose the aero glass interface when using integrated graphics on battery power.

Finally, make your HD spin less:

"Together, your hard disk drive and your DVD drive can account for 10 percent of your power usage. By adding RAM to your system, computing instructions can be processed faster, which decreases hard drive activity and conserves power." - Intel.com

There's 2 steps to accomplish this, both improve your computer's ability to cache data in flash memory (which uses very little power compared to a spinning magnetic disk), and both cost money.
1: Get more RAM. 3GB for a 32-bit OS, 4 for a 64-bit OS (due to motherboard/chipset limitations only)
2: Get Intel Turbo Memory.

"The ReadyDrive portion of Turbo Memory is designed to work with Vista's ReadyDrive technology. ReadyDrive's fundamental goal is to cache data from the hard disk to either improve performance or in the case of a notebook, improve battery life. The primary role of ReadyDrive with Turbo Memory in a notebook, is to increase battery life.

ReadyDrive can increase battery life by fulfilling data request out of low power flash memory, and keeping the hard disk spun down when not needed. If enough data is stored in the ReadyDrive partition of Intel's Turbo Memory, the hard drive can remain spun down for significant periods of time, thereby improving overall battery life. Obviously the success of ReadyDrive depends on its ability to correctly prefetch the right data into Turbo Memory's cache, but if it works, the battery savings could be significant." - AnandTech.com

In order to maximize your large amounts of RAM and ReadyDrive/TurboMemory, minimize the number of applications you have open and don't close then reopen them. Use lightweight applications whenever possible to fit lots of things in your cache and keep your HD from spinning.

Alternatively, you could buy a Solid State Drive and solve all your spinning HD problems (but not your money problems).


So putting it all together, what can I expect?

While applying all the above except buying a SSD ($700+) and leaving wireless on, I got about three and a half hours, or ~200 minutes. I probably could have stretched it to 4 hours, but I actually ran a few other programs like 3dMark06 (for a moment), and downloaded a lot of stuff (which crazily uses up wireless power).

I had firefox, openoffice, and pidgin (aim client) all running and frequently alt-tabbing between them. I also had the Vista Sidebar open with the CPU Usage and Network Meter gadgets running.

Note that battery life estimates given on the Notification Area fluctuate a lot and gain accuracy as your computer settles down after start-up.

I heard estimates of 4.5 hrs of battery life with the smart bay battery... but that seems wrong. It'd probably reach something like 6-7 hrs.

Very nice. I will definitely be using this guide once I get my m15x. +1

Steve, sticky this.

Excellent post Koshinn! Same as Spartan, I'll be using this once I hopefully get mine :P

Wow, great tutorial!!
Should be Stickied!
If I get a 1920 X 1200 screen resolution will that affect the power consumption?
Also, the Alienware head on the m9750 can be turned off by pressing fn+f10, will it work on the m15x?

I'm not sure if the screen res affects the power consumption. Maybe.

Yes, there are different lighting zones on the m15x. And the Alienware Head is one of them. You can even turn it off and keep everything else on if you want.

yes the higher the screen resolution the more juice its going to take to show all those pixels...

if u have more pixels to power up its going to take more power its not going to be a big difference but there will be some... its like it takes more power to light up new york city than it does like los angeles... more people more power...

Yes it'll take a little more power with higher res. The main thing that takes up power in a LCD, however, is the backlight, not the pixels themselves. So if there is a difference in power usage, I don't see it being very pronounced.

Can you do some battery tests on your max resolution settings and lowest resolution setting?

I'd honestly rather not. I don't want to surf the net for 4 hrs straight without doing anything else

How bout the estimates for the battery lifes when you change the resolutions?
How much extra time do you get if you lower your resolution?

I think it will be the same vcw. Even if you change the res to 1280x720 it won't automatically get rid of the other 500+ pixels.

Yeah, you'd have to actually change the hardware.

It's actually a lot more than 500 pixels.

1440 wide, 900 tall
vs
1280 wide, 800 tall (same ratio)

There's a bar on the side that's 160 pixels wide and 900 tall that's missing
and a bar on the bottom that's 100 pixels tall and 1440 wide that's missing. There's also some overlap.
So the number of extra pixels is 160x900 + 100x1440 - 160*100
Which is 272,000 pixels. Which seems like a lot, but 1440x900 has 1.296 million pixels.

So actually 1280x800 is about 80% as big as 1440x900.

lol. Yeah, I know...it was a guestimate. Just trying to get my point across.

I just realized you can also disable the built-in camera with Fn+F9, but I haven't noticed any battery life increase. Edited the first post.

Sticky?