Gateway E-155-C: A Lightweight Convertible
by Jarred Walton on July 4, 2007 12:05 AM EST- Posted in
- Laptops
Battery Life
In the past, our standard battery life test has been provided courtesy of MobileMark 2005. Since we're now moving towards testing with Windows Vista (which MobileMark 2005 doesn't support), we needed to come up with a new method to determine battery life. Generally speaking, we don't expect people to seriously tax their laptops when they are unplugged, so we tried to create benchmarks that will simulate normal use.
For the first battery test, we use Internet Explorer to simulate surfing the web. We have a script that starts Internet Explorer and loads our three homepages, all of which contain quite a few Flash-based advertisements. The script then sleeps for 60 seconds, simulating "reading" a web page(s), after which Internet Explorer is shut down and reloaded. Internet Explorer is set to delete all temp files on exit, in order to continue to generate hard drive activity. The other battery life test is simply DVD playback, and we use Star Wars Return of the Jedi as our test DVD. Basically, the Internet Explorer test corresponds to about the best case scenario you are likely to encounter, while the DVD test is a bit more taxing.
Gateway sent us both their 4-cell and 6-cell batteries for testing. The results are summarized in the following table, along with scores for the HP dv6500t.
The default 4-cell battery doesn't provide a lot of battery life unless you turn down the display brightness. Since we felt the display was already relatively dim, we certainly wouldn't want to use the laptop at reduced brightness settings. However, for the record we were able to improve battery life by 30 to 35% by running the display at minimum brightness. Moving to the 6-cell battery increases battery life by about 50%, as expected. In the near future, Gateway will also begin shipping 8-cell batteries - they are already selectable in the online configurator.
Another anomaly that cropped up concerns brightness, so we'll address that now. Windows Vista would periodically adjust the display brightness while we were using the system, for no apparent reason (though not during our battery benchmarks, thankfully - it appears to be related to input from the keyboard/mouse). Sometimes the LCD would get darker, and sometimes it would get lighter. The E-155-C has three keys that allow you to adjust the display brightness. Two of these are used to increase or decrease brightness, while the third appears to cycle between three settings (minimum, medium, and maximum). Unfortunately, for some reason Windows Vista disables the increase/decrease brightness keys. (We experienced the same problem with the HP dv6500t.) We would assume this is another driver issue, though whether it's the display drivers or something else we can't say.
Power Consumption
Related to the battery life discussions we've just finished, we have power results. For power testing, we remove the battery from the laptops and measure system power draw at the wall outlet using a Kill-A-Watt device. We test several different scenarios to try to isolate the power draw of the various components. First, we have the baseline measurement when the system is idle and sitting at the desktop. No applications are running for 10 minutes or more but the screensaver and hard drive sleep mode are disabled. As a CPU load test, we run the SMP version of Folding@Home at 100%. Finally, for maximum power load we leave Folding@Home running and start 3DMark05. In this way, we can see roughly how much power the GPU is using in 3D mode versus 2D mode.
The E-155-C doesn't consume a lot of power, and clearly a large portion of the power is going to the display. The difference between maximum and minimum brightness is about 5W, so maximum brightness increases idle power consumption by over 30%. The maximum power draw of the system when the CPU is under full load increases by 9W, so the display still increases total system power draw by 20% under load. Given the relatively small battery capacity, every additional watt of power draw can have a noticeable impact on battery life. We're looking forward to testing some laptops that use LED backlighting to reduce the LCD power requirements without compromising on brightness levels.
In the past, our standard battery life test has been provided courtesy of MobileMark 2005. Since we're now moving towards testing with Windows Vista (which MobileMark 2005 doesn't support), we needed to come up with a new method to determine battery life. Generally speaking, we don't expect people to seriously tax their laptops when they are unplugged, so we tried to create benchmarks that will simulate normal use.
For the first battery test, we use Internet Explorer to simulate surfing the web. We have a script that starts Internet Explorer and loads our three homepages, all of which contain quite a few Flash-based advertisements. The script then sleeps for 60 seconds, simulating "reading" a web page(s), after which Internet Explorer is shut down and reloaded. Internet Explorer is set to delete all temp files on exit, in order to continue to generate hard drive activity. The other battery life test is simply DVD playback, and we use Star Wars Return of the Jedi as our test DVD. Basically, the Internet Explorer test corresponds to about the best case scenario you are likely to encounter, while the DVD test is a bit more taxing.
Gateway sent us both their 4-cell and 6-cell batteries for testing. The results are summarized in the following table, along with scores for the HP dv6500t.
| Battery Life (Minutes) | ||||
| HP dv6500t 6-cell | HP dv6500t 12-cell | Gateway E-155-C 4-cell | Gateway E-155-C 6-cell | |
| Internet Explorer (Max. brightness) | 133 | 246 | 111 | 168 |
| DVD Playback (Max. brightness) | 105 | 205 | 98 | 146 |
The default 4-cell battery doesn't provide a lot of battery life unless you turn down the display brightness. Since we felt the display was already relatively dim, we certainly wouldn't want to use the laptop at reduced brightness settings. However, for the record we were able to improve battery life by 30 to 35% by running the display at minimum brightness. Moving to the 6-cell battery increases battery life by about 50%, as expected. In the near future, Gateway will also begin shipping 8-cell batteries - they are already selectable in the online configurator.
Another anomaly that cropped up concerns brightness, so we'll address that now. Windows Vista would periodically adjust the display brightness while we were using the system, for no apparent reason (though not during our battery benchmarks, thankfully - it appears to be related to input from the keyboard/mouse). Sometimes the LCD would get darker, and sometimes it would get lighter. The E-155-C has three keys that allow you to adjust the display brightness. Two of these are used to increase or decrease brightness, while the third appears to cycle between three settings (minimum, medium, and maximum). Unfortunately, for some reason Windows Vista disables the increase/decrease brightness keys. (We experienced the same problem with the HP dv6500t.) We would assume this is another driver issue, though whether it's the display drivers or something else we can't say.
Power Consumption
Related to the battery life discussions we've just finished, we have power results. For power testing, we remove the battery from the laptops and measure system power draw at the wall outlet using a Kill-A-Watt device. We test several different scenarios to try to isolate the power draw of the various components. First, we have the baseline measurement when the system is idle and sitting at the desktop. No applications are running for 10 minutes or more but the screensaver and hard drive sleep mode are disabled. As a CPU load test, we run the SMP version of Folding@Home at 100%. Finally, for maximum power load we leave Folding@Home running and start 3DMark05. In this way, we can see roughly how much power the GPU is using in 3D mode versus 2D mode.
| System Power Draw (Watts) | |||||
| ABS Mayhem Z5 | ASUS A8JS | ASUS G2P | Gateway E-155-C | HP dv6500t | |
| Idle | 44-49 | 26-32 | 43-52 | 16-21 | 22 |
| 100% CPU | 67-71 | 47-52 | 71-81 | 25-30 | 57 |
| Maximum | 100 | 71 | 97 | 34 | 67 |
The E-155-C doesn't consume a lot of power, and clearly a large portion of the power is going to the display. The difference between maximum and minimum brightness is about 5W, so maximum brightness increases idle power consumption by over 30%. The maximum power draw of the system when the CPU is under full load increases by 9W, so the display still increases total system power draw by 20% under load. Given the relatively small battery capacity, every additional watt of power draw can have a noticeable impact on battery life. We're looking forward to testing some laptops that use LED backlighting to reduce the LCD power requirements without compromising on brightness levels.
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DEMO24 - Wednesday, July 4, 2007 - link
stylus is the only way to make commands work on the screen.also if you configure the stylus right, then having the issue mentioned in the article is not a problem.
I carry a tablet around where I work. While I don't use the tablet function, its been pretty damn reliable. They seem to be a bit more durable than a normal laptop. This thing has seen its fair share of abuse, and it's never missed a beat.
JarredWalton - Wednesday, July 4, 2007 - link
You can interface with the display using a finger, but for a variety of reasons I would definitely recommend the stylus. You get better accuracy, you can easily click or right-click, and you don't leave fingerprints everywhere.Vidmar - Wednesday, July 4, 2007 - link
Page 10: The chart says "Batter Life". I guess you can't have your cake and eat it too! ;)Vidmar - Wednesday, July 4, 2007 - link
I wonder if you could get better battery life under XP tablet instead of Vista? Our E-155Cs are getting ~240-260 mins of battery life with the six cell battery under XP tablet while doing routine tasks and the display fully bright. (Which I agree is necessary)Also you had mentioned in the article that the display would dim sometimes all on its own. There is a BIOS option, ALS control (Ambient Light Sensor) that allows the machine to control display brightness using a sensor on the laptop. This reason for this option is when you would want/need to use it in daylight. The sensor senses the extreme brightness of daylight and lowers the brightness of the display so that it can be read in full sunshine. Unfortunately I think it’s a bit more sensitive and can also lower the display brightness when it really should not. This can be simply disabled in the BIOS.
JarredWalton - Wednesday, July 4, 2007 - link
It wouldn't surprise me if XP lasts a bit longer in terms of battery life. Vista seems like it tends to keep the CPU in a higher performance state, at least on other laptops. The HP dv6500t, for example, rarely ran at lower than 1.6 GHz, even though it could go as low as 800 MHz (or perhaps 1 GHz?). One of these days I'll have to do a better XP vs. Vista laptop comparison, just to see how things stand.MercenaryForHire - Wednesday, July 4, 2007 - link
Or at least beaten with a hose. I haven't used a telephone cable for anything other than the household phone for about ten years.And while the forward location of the (only) two USB ports makes it easy to pop in a memory stick or other peripheral, it makes using a mouse more than a slight nuisance as the cord will have to snake backwards across the optical drive.
Vidmar - Wednesday, July 4, 2007 - link
One aspect of this table pc that was missing from this article was that it also can be configured with Bluetooth. A Bluetooth mouse is the perfect companion for this machine. No wires, USB wireless adapters necessary.bldckstark - Friday, July 6, 2007 - link
USB wireless mouse = $12Bluetooth mouse = $80
Extra 3lbs of batteries you have to carry for the Bluetooth mouse = Priceless
At least that's what my Chiropracter said.
If you have to plug in a USB device to run your mouse, why not just use a wired one? Why bother with the batteries.
Visual - Wednesday, July 4, 2007 - link
that laptop is utter crap, it seems.only people that really want something ultra-light and don't care for performance at all would be interested... and they would be better off with a pda or smartphone, with an additional portable keyboard if they need a lot of typing.
i dont understand why laptop makers don't make a decent convertible - at least 13-15", with reasonable graphic card and all... and even bigger laptops, even if they're not too comfortable for holding in one hand can still benefit from a touchscreen and a tablet-like folding.
Vidmar - Wednesday, July 4, 2007 - link
This laptop/tablet is for those who need to run a queries against an database, while programming that new interface for the next rev of the accounting app, while reading their email, while taking notes tablet style, all while connected to the corporate VPN and never having to touch an electrical outlet for ~4.5 hours in those day long meetings.Do that on your PDA.