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Battery Life: MBP 15"

R

rickeames

macrumors 6502
Original poster
Mar 12, 2008
392
71
Wow, I have been forcing integrated graphics for so long that I had a different view of the universe, but having bought a 27" display, I had to put discrete on. My battery life never shows greater than 3 hours now! WTF is that all about?

Is it really that bad under discrete? And why does Reeder force discrete on? It's just showing RSS feeds!
 
rickeames said:
Wow, I have been forcing integrated graphics for so long that I had a different view of the universe, but having bought a 27" display, I had to put discrete on. My battery life never shows greater than 3 hours now! WTF is that all about?

Is it really that bad under discrete? And why does Reeder force discrete on? It's just showing RSS feeds!
Click to expand...

Why are you using your MBP with a 27" display on battery? Can you even do that? I can't with my 24" ACD. But yeah, some weird programs trip it too - like Papers. Why do I need discrete graphics power to read pdf's? You can push back with gfxCardStatus etc.
 
rickeames said:
My battery life never shows greater than 3 hours now! WTF is that all about?Is it really that bad under discrete?
Click to expand...
Well it just adds up in that situation. If you run a normal desktop PC using one monitor lets the GPU run in its lowest power state. If you have 2 Monitors it never enters the lowest power state. That is just how it is unfortunately.
http://www.computerbase.de/artikel/...adeon-hd-7970/15/#abschnitt_leistungsaufnahme
It ist German but down where it says Dual-Monitor and the lower table with the "Zwei Monitor Betrieb" is bars of power consumption of those GPUs with 2 Monitors not doing anything more than on idle. Compare them with the idle values on the top of the page. For the 7970 vs Intel HD 3000 it is 66W vs 52W on idle (one monitor) but 104W vs. 57 in dual monitor setup. (Those values are total system power everything included CPU,Hdd, mainboard...) In both cases the cpu sits idle and the GPU has nothing more to do than display some more or less static desktop.
It is just that for some reason GPUs never use many power saving features with 2 monitors attached. It isn't all that much different with mobile GPUs. Nvidia GPUs do much better in that comparison but the slower the GPU the more difference there is between 1 monitor idle and 2 monitor idle, relatively in my experience form reading such stats of older and slower hardware.
Ergo it is not as bad as it looks if you only run one monitor it should show much better battery life.
rickeames said:
And why does Reeder force discrete on? It's just showing RSS feeds!
Click to expand...
Apple's auto switiching implentation is really poor that is no other way to put it. They started wrong and instead of fixing the error and start from the beginning again they stuck with it for now. I hope they bring an Optimus/ADS like solution in the next iteration which would allow much more reasonable switching, with less bugs, based on actual requirements and also allow the use of an IGP with a 2nd Monitor in use.
If I use two monitors I rarely to more demanding stuff than watching videos and the IGP could handle that easily. I only need my dedicated GPU for gaming in Windows. Oh yes and doing it right would also allow the use of existing Optimus/ACD Windows drivers without too much hassle. Currently they'd need to write a seperate driver and considering how poor their job was with the first they never bothered for Windows.
 
Last edited:
FuNGi said:
Why are you using your MBP with a 27" display on battery? Can you even do that? I can't with my 24" ACD. But yeah, some weird programs trip it too - like Papers. Why do I need discrete graphics power to read pdf's? You can push back with gfxCardStatus etc.
Click to expand...

Problem is, I think the OP has a new MBP with a TB port. Only the discrete graphics card is connected to it, so if the OP wants to use a monitor, the dedicated hard has to be enabled.
 
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GuitarG20 said:
Problem is, I think the OP has a new MBP with a TB port. Only the discrete graphics card is connected to it, so if the OP wants to use it for a monitor, the dedicated hard has to be enabled.
Click to expand...

Yes, that's it, but when I'm running off monitor, I don't want Reeder forcing my MBP to run for only 2 hours. That's awful.
 
The discrete GPU supports more graphics acceleration options than the integrated GPU. Applications that are coded to use the best available graphics option will make OSX switch to the discrete GPU. Unfortunately right now the only options are either to use gfxcardstatus or to stay away from such applications.

External displays are a different issue. The integrated GPU is not connected to the display port, so whenever you want to use an external screen you have to activate the discrete GPU. I'm not sure why this is a problem, since the external screen also needs a power source... so just plug in the mac.
 
thundersteele said:
The discrete GPU supports more graphics acceleration options than the integrated GPU. Applications that are coded to use the best available graphics option will make OSX switch to the discrete GPU. Unfortunately right now the only options are either to use gfxcardstatus or to stay away from such applications.

External displays are a different issue. The integrated GPU is not connected to the display port, so whenever you want to use an external screen you have to activate the discrete GPU. I'm not sure why this is a problem, since the external screen also needs a power source... so just plug in the mac.
Click to expand...

much clearer than mine... i guess mine didn't make much sense...
 
3 hours sounds about right for dedicated graphics use. You must use the discrete graphics when using an external monitor. In fact if you tried to force the integrated, the computer would simply not detect the external monitor.

Anyways if you're using your external monitor, odds are you have a power source, so I don't really see an issue.
 
Simplicated said:
Yep, running with discrete all the time kills battery.



Core Animation forces the machine to use discrete, and Apple doesn't provide a way to circumvent this.
Click to expand...

Actually Apple does provide a way to circumvent this in Lion but it's relatively new and most programs aren't using it yet. Adding the NSSupportsAutomaticGraphicsSwitching key to the plist will work for some apps but it doesn't seem to work for most app store apps.
 
Has 10.7.3 resolved the battery life issues? I have an early 2011 15" MBP and when I run on integrated it gives me 4 hours max. There's usually no difference between discrete and integrated.
 
zflauaus said:
Has 10.7.3 resolved the battery life issues? I have an early 2011 15" MBP and when I run on integrated it gives me 4 hours max. There's usually no difference between discrete and integrated.
Click to expand...

have you reset your SMC since updating to whatever version of 10.7(?) you're on?
 
I run [as required] discreet when connected to AC and my 24" display, but just use gfxCardStatus when I'm mobile (battery, built-in display) to force integrated graphics. Seems like a pretty simple solution.

@rickeames .. if you haven't tried it:

http://www.macupdate.com/app/mac/33905/gfxcardstatus

Runs in the toolbar, just force integrated when not running your external display, and I _believe_ it overrides any kind of application level request for the discreet GPU[?]

Just remember when you return to your external, you'll need to manually switch back to discreet (or auto) ... that's got me a couple of times, thought my monitor had crapped out :D
 
D.T. said:
@rickeames .. if you haven't tried it:

http://www.macupdate.com/app/mac/33905/gfxcardstatus

Runs in the toolbar, just force integrated when not running your external display, and I _believe_ it overrides any kind of application level request for the discreet GPU[?]
Click to expand...

That's correct. It overrides any app requests and runs the GPU you tell it to. However, it's a little buggy on 10.7 right now. I still use it, and the developer told me that he's planning to release an update fairly soon.
 
zflauaus said:
I'm on 10.7.2 and yes, I have. Drained the battery a few times as well. I'll give it another reset.
Click to expand...

I think it would make more sense to focus on what is using up your battery, instead of messing around with the battery itself.

Use activity monitor and coconut battery to find out when your power usage is the highest and which processes are causing it.
 
thundersteele said:
I think it would make more sense to focus on what is using up your battery, instead of messing around with the battery itself.

Use activity monitor and coconut battery to find out when your power usage is the highest and which processes are causing it.
Click to expand...
I have. There's usually nothing over 10% at any given point. coconutBattery shows my battery health at 95%.

Reset the SMC. Nothing changed.
 
zflauaus said:
I have. There's usually nothing over 10% at any given point. coconutBattery shows my battery health at 95%.

Reset the SMC. Nothing changed.
Click to expand...

what does coconutbattery show your watt usage as most of the time?
 
rickeames said:
Yes, that's it, but when I'm running off monitor, I don't want Reeder forcing my MBP to run for only 2 hours. That's awful.
Click to expand...

You're tethered to a desk with your display, why the heck aren't you plugging in the machine?!?
 
GuitarG20 said:
what does coconutbattery show your watt usage as most of the time?
Click to expand...
Never really paid attention to that little statistic. When I have Twitter.app and Chrome running with a few tabs and I'm actively browsing sites, it's about 18-22 watts. If let it sit and do nothing, it's 14-16 watts.
 
zflauaus said:
Never really paid attention to that little statistic. When I have Twitter.app and Chrome running with a few tabs and I'm actively browsing sites, it's about 18-22 watts. If let it sit and do nothing, it's 14-16 watts.
Click to expand...

that seems fairly in line with mine, which is a 2.2... seems like that's fairly accurate. and with the battery size of the 15" (how many mAh?) it seems about 3-4 hours is right.
 
GuitarG20 said:
that seems fairly in line with mine, which is a 2.2... seems like that's fairly accurate. and with the battery size of the 15" (how many mAh?) it seems about 3-4 hours is right.
Click to expand...
My battery currently hold 6565mAh. I don't believe it's right because when I ran Snow Leopard it was a solid 7.5-8 hours of usage like they advertise.
 
zflauaus said:
Never really paid attention to that little statistic. When I have Twitter.app and Chrome running with a few tabs and I'm actively browsing sites, it's about 18-22 watts. If let it sit and do nothing, it's 14-16 watts.
Click to expand...

Idle my machine sits around/below 10 W, browsing with Safari I usually stay below 15W and about 12-13 W average. That gives me about 7 hours.

Display 12/16
Bluetooth off
gfxcardstatus set to integrated

I'm using flash and adblock, no other plugins. Power usage goes up when using flash, but a few minutes of youtube videos don't hurt my battery very much.

I don't know whether twitter.app is resource hungry, but ~ 15W when idle sounds like a bit too much for a long battery duration.
 
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