> According to the reviews, the optional 6 cell battery gets you 4 hours - > there isn't a larger battery option at all on the eee, so I would count > that as improved battery life... > > Vern
I delayed responding to this until tonight when I could find some time to finish getting all the details. The 6 cell battery for the (wh)eee pc is still "coming soon". I suspect it would probably be out before very much longer. Battery life and heat goes hand in hand. The less heat that you generate, the more battery life you get. Simple power engineering, right? The eee pc uses a celeron M ULV 353. It requires a fan as it gets fairly hot (not on the cpu, but on the chassis). So it doesn't quite reach it's goal of being completely devoid of moving parts. Now HP is apparently using a VIA 1.2/1.6 GHz VIA C7-M processor. According to VIA that means it's about 12 watts to 15 watts of power at peak. http://www.via.com.tw/en/products/processors/c7-m/c7-m.jsp The wheee pc uses a Celeron M ULV 343 which uses 5 watts of power. http://www.intel.com/pressroom/kits/quickreffam.htm But as we all know, it's not the peak power that matters but average power. For instance if you're not using SSE(2) extensions, those could actually be powered off inside the CPU. Also, if there's an idle state, the cpu can power itself off until something requests CPU time again. On the bottom of the wheee pc there's a sticker that says that the adapter must be able to supply 22 watts of power. So that means 17 watts of power is split between the screen, the chipset, recharging the battery, and the display. Now the wheee PC gets warm even during idle use, this suggests bad power engineering. So where can you save power? Making sure idle components enter into a "low-power" mode. Using efficient chips for power conversion between different voltages. Using efficient light for the back light, etc. So let's dig in a little more. Look at this picture. http://www.tweaktown.com/popImg.php?img=eeepc6_l.jpg You can see that the wheee pc's fan sits over what appears to be a couple voltage regulators and a couple of coils. Note that when the eee pc is put back together the fan sits directly underneath those items. I'm guessing those are getting hot. The fan would not do very much for the CPU and chipset, since those are sitting on top of the board, and you can see their picture here: http://www.tweaktown.com/popImg.php?img=eeepc5_l.jpg There also don't seem to be any vents on the keyboard side of the chassis. The only vents are on the underneath with the fan. http://www.tweaktown.com/popImg.php?img=eeepc22_l.jpg So yeah, I'm guessing that there's no reason the eee pc could not have been made to be more power efficient. They used a pair of bad regulators and then had to add a fan when it got too hot. When people tear into the HP, it would be interesting to see if the HP has fans and where they are. Typically one would expect the CPU and the chipset would be the hottest thing running in the chassis, afterall, they're doing most of the switching. --R _______________________________________________ Fwlug mailing list [email protected] http://fortwaynelug.org/mailman/listinfo/fwlug_fortwaynelug.org
