New MBA 13 only lasts 3-4 hours using MS Word!

[ZBoater]

Therein lies the folly of Haswell. Power savings are at idle (lower clock speed), but when TurboBoost kicks in, the clock speed essentially doubles, and poof, there goes your battery! Probably MS Word is causing T/B to kick in every time it autosaves or spell-checks.

This is very interesting. It is unreasonable to expect that much better performance with equal or less battery life. The extra battery life has to come at the expense of something. But using a word processor shouldn't be it...

 

[johngwheeler]

Although, saying that, I'm running Word now (updated ofc) and it's running just fine, no more than 5% CPU usage for my whole system, on lots of text and photo heavy docs. Maybe it is an issue with your machine?

I've seen spikes in CPU when using Word 2011 on all 3 Macs I have owned, so I dont' think my machine is faulty - if I close Word, battery estimates are in line with Apple's claims.

How large were your Word documents and were you working in them, or did you just have them open? I'd like to try to see if I can duplicate your usage fairly closely to see if it's a problem with Word or with your MBA.

I was working with 4 docs, averaging about 100 pages each. Grammar and auto spell-check are disabled. I've also removed fonts from the Mac OS Font Book that fail the compatibility test.

I opened a 40 page document, typed in another 3 or 4 pages today and at the end the battery had gone from 100% to 90% in about 45 minutes. Thats about what I would have expected, given it was also connected to WiFi, Bluetooth mouse connected and screen brightness was a little over 50%.

This seems to be pretty much what I saw at first. I thought "OK, I should get 7-8 hours; not stunning, but pretty good". However, the estimated time remaining decreases non-linearly, so that a 10% = 45 mins, became 10% = 30 min, then 10% = 20 min. I didn't run the battery completely flat using Word, which I should try one day.

I did find that once I close Word (battery was at about 70% I think), that I got about another 6 hours out of the machine until it died with moderate web browsing (Chrome), mail (PostBox), Preview docs (may 6 open) and Evernote.

The power estimates are way off. I have safari, unity, monodevelop, word, and outlook open and i get between 10-12 hours of battery life. My estimate says 6.

You may be right. The ultimate test is actually using the machine, but it would be helpful if the estimates were more accurate so one could plan when you need to find a power outlet.

I don't think any word processor is dramatically draining anyone's battery.

But mine does! And this is my point - a word processor *shouldn't* tax a modern computer - it's a glorified text editor FFS. If it's not doing a spell check, running some macros, or something that is obviously "processing", all it should do is occupy memory with very low CPU cycles. I can't understand why I often see my MS Word process at 99% (i.e. one full core of my 2 core machine.)

I will try Libre Office (again), when working on documents that I don't have to regularly share. I can live with doing some reformatting in MS Word once of twice, but if you're working in a team on a shared document, then LibreOffice/OpenOffice is unacceptable - it generally screws up something in the formatting every time it moves between MS Word (Windows) & Libre Office.

This does raise the general question of how good is MBA battery life under various CPU loads. It's all well and good to say "I get <nn> hours running application <xx>", but without knowing what resources application <xx> uses, you don't have an absolute measure.

It would be good to create a graph of CPU usage vs Battery life, e.g. at 50%, 100%, 150%, 200% CPU (assuming 2 cores) - how long will it last? I bet people doing Handbrake encodes don't get a lot of time!

 

[halledise]

try an SMC reset first before returning the machine and see how you go

http://support.apple.com/kb/ht3964

 

[gabberkooij]

The only apps I had open were 4 (quite large) MS Word 2011 docs, Evernote, Stickies & Finder. Wi-fi was turned off. Screen brightness was at 50%

A quick look at Resource Monitor didn't show any "rogue" processes eating CPU, but MS Word was occasionally peaking at 70-80% CPU, which in my experience with MS Word on Mac, is unfortunately normal.

I'm very interested to know if this behaviour is the same when things like auto correction are off.
And if this behaviour is also happening for other Air users. It could mean that with regular Word use you're better off with a i5 Air.

 

[johnjey]

Viewing movies is fine. As long as you don't use Silverlight (another fine Microsoft product). 10 hours of h.264 movies should be no problem.

Where in the world will you find h264 video's online ? Netflix loves silverlight and so does most of the other websites

 

[johngwheeler]

I'm very interested to know if this behaviour is the same when things like auto correction are off.
And if this behaviour is also happening for other Air users. It could mean that with regular Word use you're better off with a i5 Air.

Auto-correction, spelling-check and grammar check are all disabled.

I have the feeling that CPU load may be related to both the size of the document, and with the amount of moving around the document (i.e. scrolling through large numbers of pages). Maybe there is some kind of paging going on between physical and virtual memory spaces (although I have plenty of free RAM and no indication of frequent page-outs)

 

[johnjey]

Its insane and amazing at the same time that how we all apple fanboys are trying to make sure to take every possible step in the world to squeeze out juice from the battery for a longer amount of time, a windows dude will simply slap bill & walk out and not give a damn about closing 10 different applications or doing tweaks to adjust his battery lol

 

[KPOM]

Whilst this fairly clearly shows that MS Word is the culprit, it also means that the 12-hour battery life claim is probably only valid if the computer is being very lightly used - i.e. a couple of text files or browser tabs - and not playing video, running Flash, compressing files, encoding video/audio or anything else that uses more than a few % of CPU capacity.

I read another thread comparing i5 & i7 battery life, with some test results that showed only a couple of hours remaining charge after playing a single HD movie.

[In case anyone suggests I don't use MS Word, this is not an option for me as I have to share work with Windows users, and nothing except MS Word for Mac is sufficiently compatible!]

I'd try reinstalling Office. A bad installation could cause the CPU cycles to ratchet up (I've also seen that happen when system files are corrupted). I get longer than that in Word on my 13" rMBP.


FWIW, here is Anandtech's results with the 13" i5 and i7 models:
http://anandtech.com/show/7113/2013-macbook-air-core-i5-4250u-vs-core-i7-4650u/4

 

[aarond12]

Where in the world will you find h.264 videos online?

YouTube would be one. Some other adult sites would be another.

 

[DisplacedMic]

so is using word a no go if your trying to save battery power? has anyone tried using pages instead or another writing app?

no - there's something wrong with this guy's computer and he should just bring it in and have them fix or replace it.

 

[johnjey]

YouTube would be one. Some other adult sites would be another.

Lol..please share those links for those sites...ofcourse not openly but via message

 

[vistadude]

Did you actually close all the other apps? Pressing the X button does not close apps. Also how many documents did you have open, how many images and what resolution were they?