Two of the Worlds most Energy Efficient Mobile Internet Devices launch on Friday.

Posted on 10 July 2008, Last updated on 11 November 2019 by

iphone3gsmallEnergy efficiency is, without a doubt, the most important design factor for any pocketable Ultra Mobile device. On Friday this week, there are two very important launch events taking place that will highlight the advances made in energy efficient computing over the last year. The two devices will also show how us close Intel and ARM partners really are in the race to provide handheld, Internet-focused computers. MIDs.

On one side of the fence, in PC land, Sharp and Willcom will release a pocketable slider-keyboard mobility-focused device. The Sharp Willcom D4 will be running Windows Vista on the Intel Silverthorne/Poulsbo platform also known as Menlow and is likely to be one of the most energy-efficient 3G-enabled PC’s so far.

On the other side of the fence, in smartphone land, Apple will release a smaller, 3G-capable mobility-focused device running a highly optimised desktop operating system. The iPhone 3G will be running ARM-based processors and is likely to be one of the most energy-efficient 3G smartphones so far.

The Willcom D4 is said to have (independent tests) a 3G-active time (Internet activity) of around 1.5 hours and it runs a 7wh battery.

The iPhone 3G is said to have (Apple figures) a 3G-active time (Internet activity) of around 5 hours and it is likely to run (my estimates) a battery of about 5.5wh.

3G-active Internet time is a worst-case measure of device efficiency so, based on these early figures, it looks like the Menlow-based device will use about 4.5W and an iPhone will use about 1W.  More after the pic…


Both figures are very impressive. In my own tests I’ve only been able to achieve figures of about 9W for a 3G-enabled mobile PC (Everun+3G) and about 2W for a 2008-class 3G smartphone (N82) under similar load conditions. Both new devices appear to be 2x more efficient which is good news for everyone. Its a huge step forward.

In terms of raw processing power though, the 1.3Ghz X86-based Silverthorne in the Willcom D4 is likely to be at least as powerful as an Eee PC 701. This is 6-8 times as powerful as the iPhone. (Based on ARM11 performance. This is the range of figures I’ve seen put forward.) so the figures still need normalising. Somewhere in the middle, is the sweet-spot that many of us are looking for.

By the end of Friday, we will probably have the first real-life battery life reports for both platforms and we’ll be able to see exactly how far the PC world is from the Smartphone world in terms of power efficiency. Either way, Friday is going to be a great day for Ultra Mobility.

22 Comments For This Post

  1. Vakeros says:

    So based on what you have written, the D4 is roughly twice as efficient as the iPhone. I state this because it is 6 – 8 times more powerful, but a quarter of the life.
    I notice in the figures these are Apples figures so independently it could be found to be less. Is the iPhone the most efficient 3G smartphone? As a consumer I would be asking the question – What can I do with the D4 I can’t with the iPhone? If the answer is not a lot then the iPhone would be the way to go, purely because it lasts longer and is subsidised price.

  2. Synced says:

    Sorry to say but many 3G Windows Mobile phones last much longer than the iPhone does.

    The iPhone is actually one of the worst battery drainers in the Smart Phone category. Most of this is due to its large processor. The iPhone OS requires a significant amount of hardware to power its browser and UI. Their kernel / OS was not trimmed down that well in its initial version. I look for this to improve in the next major revision of the OS (3G is not a major revision of the OS).

    BlackBerry’s as well pretty much top Smart Phone battery consumption. Their OS probably has the smallest requirements out there for horse power needed to run the OS smoothly.

    I would like to see some metrics on what Smart Phones your comparing to the iPhone in usage longevity.

  3. Dunstan says:

    Chippy, you meant “sweet-spot”… The “sweat-spot” is where the engineers are right now, trying to achieve the sweet-spot. ;-)

  4. chippy says:

    Thanks Dustan

  5. Fixup says:

    The D4 is heavier and larger than oqo and has a more efficient Atom CPU vs. VIA C7, same screen size, but only half of the battery run time. Yes, I use OQO daily with 3G or WiFi, always get 2.5 hrs or more.

  6. Al says:


    The D4 is a full blown Windows Vista computer that is the huge difference! Plus it provides a better form factor of a clamshell and slider to make use of the full keyboard which is crucial for a full Windows computer to be of any use in the real world. I think this is not a fair comparison as the Iphone is great for a phone but its just a phone with internet it was never intended to be a real computer. The D4 has the same features as a laptop but has phone/wireless features but not meant to be a phone only.

  7. Al says:

    The D4 has an optional battery that increases the height a little but still enables it to be jacket pocket in size but increases the battery life to somewhere between 4-5 hours. I’m very eager to see real world results with wireless and just as a computer use.

  8. Richard says:

    Where are you getting the 6-8x performance numbers from? I suspect the gap will be a little closer. Here is an Intel slide

    This shows the performance of silverthorne as about 2.5 times as great as an ARM11 if they were at the same clock speeds.

    The silverthorne will be about double the speed of the ARM in the iPhone so about 5 times the performance. and this is according to Intel.

    Of course this is just one marketing slide for one type of performance measure. I hope you can link to something more technical.

  9. Symark says:

    The image/picture in this blog post is very strange!!!
    Should’nt be the other way around, with IPhone 3G on the left side with 4,5 hours efficency and Willcom D4 on right side with 1 hour?
    The comments tell exactly this:
    “The Willcom D4 is said to have a 3G-active time of around 1.5 hours and it runs a 7wh battery.
    The iPhone 3G is said to have a 3G-active time of around 5 hours and it is likely to run a battery of about 5.5wh.”

  10. Richard says:

    The graph is of power consumption of each device, it removes the factor that the D4 has a larger battery.

  11. Travis says:

    But which one is generally available worldwide without having to use greymarket/specialty exporters. Can you take the D4 to the D4 store for repair?

  12. scoobie says:

    At least you can swap the battery on the D4.

  13. Chippy says:

    Add in the increased FSB and Hyperthreading over the 1.1Ghz part and we’re up over 6x by my estimate.
    As you say, most figures are marketing figures at the moment so we’ll have to wait for independant tests (which are bound to confuse us even more!!)


  14. Chippy says:

    There’s a lot more to it than just CPU power. Graphics, radios etc etc.

  15. Richard says:

    Ah, I forgot it has hyperthreading. I still dont think Atom in any form is ready yet for these kind of devices. The Cortex A8 will be along soonish which I think will be far more suitable for MIDs.

  16. chippy says:

    Richard. I think the biggest challenge is not the CPU but the software at this point. The bar has been set so high now that anything much less than iPhone standard is going to be considered poor.
    I’m certainly looking forward to what ARM-based stuff turns up though!

  17. Will says:

    Vakeros, you should be asking yourself: “what do I want to do on these portable devices?” and then try to determine which one works best for you. Having Vista/XP on a device is irrelevant if software on a mobile platform (WM/iPhone OS/Symbian) does everything you want.

    The OQO has a much larger battery which is why it’ll last longer. Saying that, I hope that OQO will release the next model with a better screen, Menlow and a lower price.

    Synced, I’m not sure where you got your informatiom from, but WM devices are renowned for their appalling battery life. There is no way that a WM device can browse the net for 5 hours without a recharge in between.

    HTC TyTn II users (known as the AT&T Tilt in the US) don’t go anywhere without a spare battery and/or a charger.

    I’ve listend to so many podcasts where the users have complained that the new HTC Diamond has enough battery power to last until mid-afternoon.

    Samsung knows about the battery life problem so they ship 2 batteries with their WM devices along with a desktop charger!

    WM devices use similar SoCs to the iPhone and I think some may even be using the exact same Samsung SoC. The iPhone and high-end WM devices need a powerful CPU to render webpages.

    Apple have also optimised the iPhone software to offload as much processing as possible to the specialised co-processors (such as graphics, video decoding and audio decoding) on the SoC which are far more efficient than the ARM11 CPU. WM devices on the other hand have such poor software/hardware integration that a lof of features of the SoC are rarely used. HTC TyTN II users are threatening a class action against HTC because of the poor video drivers for the device!

    If the iPhone had Bluetooth PAN or DUN so I could use it as a data modem, I’d ditch my WM6 device (Samsung i780) in a heartbeat! Unfortunately it is a feature I cannot life without.

    Windows Mobile is on life support at the moment and unless a miracle happens, it will die. WM7 seems like a boring evolution of WM6 and is unlikely to entice users back to the platform.

    New devices with the next gen ARMv7-based SoCs should be appearing soon. To be honest, I’m surprised so few have been released. The only one I know that has seen the light of day is the Pandora which uses the Cortex-A8 based TI OMAP3.

    Cortex-A8… I can’t wait for WWDC 09! :)

  18. Fixup says:

    Yes oqo has a larger battery, the point is: it is still smaller and lighter than the D4.

  19. Vakeros says:

    My question was meant to be rhetorical – in other words ask yourself what you need. I like the D4, but the battery life sucks big time – no good reason why as the OQO seems to last longer.

  20. Synced says:


    I agree that WM phones have been renowned for poor battery in the phone comparisons but this has usually been in comparison to traditional cell phones and people expect equal battery life.

    I work for a mobile company and when you compare Smart Phone vs Smart Phone WM competes fine.

    Keep in mind most Smart Phones are the exact same architecture. They all run ARM processors. BlackBerry, Windows Mobile, iPhone.

    The difference is the OS requirements & bundled software.

    1. BlackBerry is tops in battery longevity. However currently they have a poor web browser and are mainly used only for email. Lower requirements = lower cpu = longer battery.

    2. Windows Mobile has a wide range of devices going from 200mhz ARM processors that last all day to 624mhz (same as iPhone if I recall) that do not last well. Just in general today for WM6 the average cpu is 400-500mhz. Not many ship with the 624mhz version but some do.

    3. iPhone is not a minimalized OS and has huge hardware requirements. It runs the current high end ARM processor (624mhz I believe, 500+ atleast).

    Rumor also has it that RIM in the new devices is using higher power processors to catch up with features and are having battery troubles. No kidding!

    So compare apples to apples when you say WM is renowned for poor batteries. It had difficulty with consumers because they were comparing it to traditional cell phones which traditionally run sub-50mhz processors.

    Btw if your saying WM is on life support, perhaps in internet hype I agree but when you look at sales numbers. MS just doubled last years-same quarter sales which is approximately 4x what apple shipped in the same quarter.

    iPhone is a very good device don’t get me wrong but people get blinded by the hype so easily. Don’t speculate, guess etc come with fact.

    Out of this entire Smart Phone fire that Apple has created (competition is good remember, it spurs innovation, intel vs amd of the 2000’s) its RIM who should be most worried. Why?

    RIM is #1 smart phone seller.
    Apple has lit a fire under MS’s ass.
    This means Apple MS are going to be innovating back at each other for the next coming years. MS is tripling their WM division size.

    So right now its RIM who has to get ready for the wave because Apple & MS are ramping up to be fast and furious.

    Sorry to take so much Smart Phone talk to a UMPC forum but I work in this space specifically and monitor UMPC’s as “the future” we may need to adopt and I like to bring realism of what happens in the mobile space oppose to hype.

  21. Al says:

    The battery life according to this from Pocketables says that the battery life was with continual WWAN usage and basic computer usage or wifi is longer use.

    The cool thing to me with the D4 is that unlike the other UMPC’s including the OQO, Sony, etc. this is the only UMPC that is both jacket pocket in size and has a normal keyboard layout. The problem with OQO is that a thumb input is just not functional for real full Windows usage. The Sony is not too wide to fit in a jacket and also suffers from the same input problems of the OQO. The other UMPC’s are much worse as they are too large to be carried in a jacket pocket and if you can not do that you eithe wear a “man purse” or you might be just better off getting a sub notebook or laptop since you have to carry it anyway.

    The D4 is in a different category that blackberries, windows mobile, Iphones, etc. as those do not have the ability to run Full Windows and thus not a full computer. The D4 can be your complete computer on the go since it runs full windows as other UMPC ‘s do but the great form factor make it much more attractive and practical to input and carry.

    Quote from Pocketables
    According to Willcom (and Babelfish):

    Approximately 3 times (4.5 hours) actualizing drive time by utilizing the WILLCOM D4 private bulk battery, by comparison with the time of substance bundled standard battery utilization! Compared to Mobile data communication of long haul becomes possible.

    Or in non-computer-generated translation terms, the CE-BL58 extended battery’s runtime is three times longer than that of the CE-BL57 standard battery. Direct From Japan (via UMPCPortal) reports that the figures listed on Willcom’s product page actually apply only to WWAN usage, so wi-fi browsing and basic computing runtimes are expected to be longer.

  22. Al says:

    Fixup Says:
    July 11th, 2008 at 3:19 am
    Yes oqo has a larger battery, the point is: it is still smaller and lighter than the D4.

    — the OQO has great technology but in the wrong form factor. That is why so few are sold (SF Weekly recently had an article which listed yearly revenue; if you divide that by the cost of an OQO its about 15K a year or if you divide by an OQO plus a few accesories it might be as low as 11K). The advantage of the D4 is the size. How does the world use full windows? they use a touch type keyboard, duh, that is why so few OQO sell each year after being on the mraket for 8 years. I’d rather have a longer clamshell with a touch type keyboard any day.

    Vakeros Says:
    July 11th, 2008 at 9:41 am
    My question was meant to be rhetorical – in other words ask yourself what you need. I like the D4, but the battery life sucks big time – no good reason why as the OQO seems to last longer.

    — I think the battery life is long enough based on the Pocketables info; I am eager to see the first reviews of the released product. Thus far the only reviews were the beta units not the final product.

2 Trackbacks For This Post

  1. 3G iPhone proves that battery life is a problem for everyone! | UMPCPortal - The Ultra Mobile Computing reference site says:

    […] little giggle, the comment also reminded me to check up on the reported iPhone 3G battery life and compare it with my figures. I came up with an interesting article from AnandTech who have completed a browsing test which […]

  2. - stories - 8133527 says:

    […] little giggle, the comment also reminded me to check up on the reported iPhone 3G battery life and compare it with my figures. I came up with an interesting article from AnandTech who have completed a browsing test which […]

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