Increasing battery life with a flash drive.

Hello all, my name is Greg and i have been looking around your forums, but this is my first thread. Tomorrow i am getting my first new laptop, and asus a8js. I have had many before but usually they were old ones that i got from people when they upgraded and i am concerned about its battery life. So i was wondering.. actually im going to try it when i get my laptop.. could you install linux or windows on a usb memory stick and actually run it directly off the usb thumb drive, making it so you never access your HDD. has anyone tried this? does it significantly increase battery life? although it would be slow because its running over usb.. what do you guys think? other possibility is using a 4 or 8gb CF card and getting a cf card to 2.5" ide adapter as a cheaper alternative to a ssd. just thinking about cool things to do.. wondering if anyone else has done it

 

You could run Linux, but you would have registry issue. You would also have to wait forever to it to boot, and to run programs off it. I am going to guess that it would eventually rev the HDD to store cache files from your programs and web pages. You would have to also have to rev the drive to load the bios to even access the USB drive. Besides, the drive would get very hot from being accessed so much. I will say that if you did, it would get better battery life, but it would be slow, inefficient, and a very big waste of time.

 

thanks nicolas, what about my second idea of using a CF card and a CF to sata adapter in the drive bay?

 

The HD will still need to spin up. It will continue to spin at a lower speed while the notebook is powered even if you are not accessing it. It only speeds up to full speed when you are loading/booting/etc.

 

I would say its most defininately not worth the effort, your battery life gain will mostly likely be minimal and not worth the effort. The screen itself is one of the biggest battery life drainers. There are also flash hard drives out, but they are extremely expensive and in low capacities so far.

 

ok yeah, thats what i figured... are there any numbers out there saying on average which components use up what percentage of power? i mean i thought Harddrive was a major one..
also i mean a 8gb cf card + sata adapter i guess would be about 200, which is less then i have seen any ssd for

 

The screen is the biggest power drain.

Take a look at this post.
http://forum.notebookreview.com/showthread.php?t=90994&highlight=news+bits
I covered an environmental utility that has a nice feature. It can show you how much power each component is using on your system. It can also help you to undervolt some settings to save power (much like Notebook Hardware Control or RM Clock would). I'm sure there are others that can do what you're asking as well.

 

Cool, thanks! For me at least i thought that the Asus a8js was the perfect laptop except for the battery life, even though ive gotten over it i still like to tweak and do interesting things to my electronic toys. Its a good thing to know that the screen definatly uses the most power in a system. I will try this out in the next couple of weeks and post my results with a CF-sata adapter. but i think since this is not really that creative, nor does it take alot of knowledge that maybe someone else has done it.

 

Your best bet to increase battery life would be to get an extra battery.

 

You would get better battery life it you put a solid state drive, they only consume 5% the power of a normal drive. But as you said, they are very expensive, and only go up to about 32gb. I have heard that someone is planning on releasing a 200gb drive sometime in the next year or two. I really hope that they come down in price soon and get capacities that are as good as the 200gb version or better.

 

i heard someone said that if the notebook have a large memory (1 or 2 Gb ram) in order to use the extra for physically memory so that the hard drive significantly run slow.so that the use of battery will be increased

Does it true or false

 

The drive still has to spin up becuase some apps use virtual memory, and the RAM itself would use slightly more power. I would think that it would not make a difference because things are always reading/ writing to the drive, and the drive is always spinning when it is just a idle.

 

what im mostly wondering is 8gb is enough for a very spartan install of windows and most common apps, if you get a 8gb cf card and a cf-sata or cf-ide adapter (if your laptop is ide) its only about 200 bucks, would the cf card be fast enough to function well, and would it significantly improove battery life, since doing it this way is alot cheaper than any solid state harddrive currently out. the 8gb cf card is rated 100x speed, so i guess thats about 20MB/sec, but it would have a quick seek time. has anyone else ever though of this? and who would do the same if it worked well?

 

The bottom line is that your HD will still be spinning, so you're still going to be using battery power to do so. I really don't think any extra battery life you get will be worth the effort. I could see the difference being negligible.

If it's really that important to you, keep an eye on the Flash HD's that are currently being developed.

 

your post vaguely has anything to do with what i said, thanks

 

How so? Unless you are planning on physically removing the HD and trying to run without it, it will be spinning and drawing power regardless of how you try to bypass its use--eliminating your chances of saving power through the Compact Flash card's use as your HD.

20 MB/sec is actually fairly slow.

 

thats eaxctly what im planning on doing, REPLACING the HD with a cf card, sorr you misundertood me

 

I apologize for misunderstanding what you were saying. Theoretically I think it might work, but you would be giving up a lot of capacity and performance (transfer speeds) to test it out.

I don't know enough about the logistics of making a bootable CF card and running entirely off it, but that could possibly cause problems with how the entire system runs. I'd hate to see you damage your brand new laptop.

 

I have 18GB at home for my O/S and all programs, and that includes a few things like photoshop and a couple games as well. At work I'm right at about 10GB, and that's with MS Office and etc.

I'd say to look at your current drive usage in GB and see if your'e even close. If you are at 5-10GB then 8 may cover you. If you have 50GB of stuff installed that you consider important to have, then obviously 8 won't be enough to replace it. You can easily answer this question on your own...

 

Also, the more full a drive (or in this case, a CF card) gets, the slower it tends to be - with the OS trying to deal with virtual memory, cache files, temp internet files, etc. etc. You might consider, if possible, two 8gb CF cards in a master/slave relationship. However, at what point to you run into diminishing returns? At some point, by the time you buy two 8gb CF cards, and two adapters, how close are you to the price point of a solid state drive? In addition, doesn't most flash memory have a limited amount of read/writes - certainly less than a HD. So, this solution would be temporary at best. It's an interesting idea, but I would be more likely to try it on an old laptop that didn't mean much to me before I'd try it with a new machine that I just laid out good money for.