Wednesday, July 06, 2005

M4 Page 7

Pages: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, Pictures

Toshiba Power Saver
I’d like to give a big thumbs-up to Toshiba here for their excellent power management utility that runs in the system tray. It allows significant control over how the computer allocates battery power (screen brightness, CPU speed, CPU fan logic, etc). One especially useful feature is that when controlling CPU speed, it can be told to dynamically adjust speed within a given range from 600 Mhz to 2 Ghz as needed based on system load, or it can be locked at a given setting. You can create your own profiles, or simply use the ones that come built into the system (which are pretty good to begin with). I have mine set to go to the High Power setting when plugged in (max brightness, CPU locked at 2 Ghz, monitor/hard drive set to never turn off), but to set itself on Long Life (min brightness, CPU adjusting between 600Mhz and 1.3 Ghz, monitor off after 1 min, etc) when running on battery power to maximize my battery life. Toshiba has spent the last few years designing and refining this power management software, and I think they’ve done a fantastic job with it.

Undervolting/Centrino Hardware Control
Based on the advice of Spybyscript (a fellow member of the forums), I downloaded a piece of software called Centrino Hardware Control and am now using it to help further fine-tune the power management by reducing the voltage sent to the processor. Usually a processor’s voltage can be reduced by a small amount without decreasing system stability, which has the side effects of reducing heat from the processor and extending battery life. It also had the somewhat unexpected (and very welcome) side effects of slightly reducing the hard drive and the GPU temperatures (I suspect because it reduces the CPU temp and they are all in fairly close proximity to each other).

After some trial and error, I was able to reduce my voltage at 2.0 Ghz (a multiplier of 15) from 1.308V to 1.132V and at 800 Mhz (a multiplier of 6) from 0.988V to 0.780V. Doesn’t sound like a whole lot (~0.2V less) of difference, but it’s translating to a lot less heat and about 20–30 minutes of extra battery life on Long Life mode.

Battery Life
I haven’t run the system from 100% down to automatic hibernation on High Power yet, but on Long Life I’m averaging about 3 hours with wireless on, light web browsing, and light inking. Before I did the undervolting and optimized the Toshiba Power Saver settings for my usage patterns, I was getting about 2.5 hours. I’ve found that the system’s estimation of how much battery you have left on the system tray to be fairly accurate, usually within about 15 minutes of actual life. I’m hoping to get that up to ~5 hours or a little better once I get the secondary bay battery. I was really hoping to get better life out of the M4, but that is one of the largest downsides to this model.

Update 7-23-05
I've been testing the secondary battery for a little over a week now and I think I'm finally ready to draw some conclusions. Under the conditions I used to test the primary battery; I've been getting 5-5.5 hours of life. With wireless off and lighter use (occasionally allowing the screen to go to sleep after 1 minute of not being used for a few minutes); battery life pushes 6 hours. If you don't constantly need the optical drive in the machine, I'd say the secondary battery is very worthwhile!

Tablet of Contents

1. Opening comments, Introduction, Convertible v. Slate, Specifications, Packaging/Contents, and Secret Decoder Ring

2. Body and Design, Build Quality Issues, Size and Weight

3. Screen Mini-Review I: Resolution, Brightness, and Glare

4. Screen Mini-Review II: Outdoor Viewing

5. Screen Mini-Review III: Viewing Angle

6. Setup, RAM Upgrade, Background Processes

7. Toshiba Power Saver, Undervolting/Centrino Hardware Control, and Battery Life

8. Timings, Video Driver and 3DMark03 Performance, and Sound

9. Software

10. Conclusion

11. High Quality Pictures


At 10:04 AM, Anonymous Anonymous said...

What is the product number of the slimbay battery?

At 8:13 PM, Blogger Shawn said...

(This is being cross-posted both as a comment in the review and as a new blog post dated 3/8/2006):
So I was taking a look at my SiteMeter today and I noticed that I suddenly started getting a whole ton of traffic from Redmond, Washington using “Microsoft Corp” as their ISP. What’s confusing about it is that they all seem to be looking at Page 7 of the M4 review (the one on the Toshiba Power Saver, Centrino Hardware Control, and battery life), but I can’t seem to figure out why that specific page is so fascinating. Either you guys are all just goofing off on company time or this is actually related to something you’re working on (maybe trying to figure out how to get more battery life out of those new “Origami” Ultra Mobile PCs?) Regardless, I still love the M4 (wouldn’t be able to survive this semester without it); so I just wanted to give you guys a shout-out and thanks for putting the tablet OS together.

As a side note (hoping to capitalize on possibly having Microsoft’s ear for half a nanosecond):
I think it would definitely be to your advantage in creating buzz for this Origami/UMPC stuff if you were to give a few units to certain members of the Tablet community/blogosphere so we can post reviews of them (people like Rob Bushway, Eric Mack, Tracy Hooten, myself [hint, hint ;) ], etc). It would be especially effective if the machines were to keep instead of being lent out for a few days or a week so we could review them as “lifestyle” machines as I gather they’re supposed to be. I know that I personally have gotten a lot of emails from people who bought the M4 because of my review and that some of the others (like Eric Mack) have had the same experience. So I think it reasonable to think that some solid reviews like that would have a similar effect on UMPC sales. I can’t speak for others in the community (although I’d guess they feel the same way), but I personally would be very willing to do another massive, good-and-bad (aka: fair), in-depth review like this in exchange for one of those devices [another shameless hint ;) ].

As a second and even more shameless side note:
I’m a Professional Flight major at Purdue graduating in a little over a year. Any chance you guys would be interested in an intern or first officer for your corporate flight department around that time?

At 10:08 AM, Anonymous Anonymous said...

Hate to disappoint you, but the hits from Microsoft are just a bunch of employees with M4s looking for a way to cut down on heat and fan noise :-)


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