Need help reducing power consumption in a laptop

Can someone please help me with a few questions? I'm a student looking for a powerful laptop and maximize battery life (by comparison to other gaming laptops)

1. Is power comsumption based on screen resolution or screen size? (Probably a combination of both?) How much more battery life could I get out of 15" screen compared to a 17" if the resolution is the same.

2. i7-620M vs i7-720QM, is the extra performance worth the ex power consumption? For the gaming I do I mainly play RTS games which would apparently run much better with a quad core?

Obviously when not connected I'll only be surfing the web and not gaming

Thanks in advance

 

If your main concern is playing games then you will want the larger capacity battery that is available for the laptop you purchase. Besides the wall outlets that you may not have available there are car adapters and large capacity exterior batteries available. I am using my laptop at home so I have everything turned up. I have the standard size battery and am lucky to get one hour of life when it is not plugged in.

 

First, find a laptop that is known to have better battery life than others. There is only so much more that you can squeeze out of what is already there.

So, do your research. You can make generalizations, but for instance, there could be a laptop with a 17" screen that could have slightly better battery life than one with a 13" screen, as much as there could be a laptop with a 11" screen with better battery life than one with a 7" screen.

 

Okay I'll add some more context then. I'll trying to decide between the MSI GX640 and GX740. They supposedly have around 2+ hours of battery life.

In theory would the GX640 with a 15" and i7-620M, 25W have a longer battery life than the GX740 with 17" and i7-720QM?

 

If the backlight is CCFL, your screen will take up to 50% of the total power drain. Pretty much anything else is in single digit percentages.

If you're serious about reducing power drain, spend the $$ for a LED backlit screen.

 

You can also wait til companies get switchable graphics working. You can reduce cost without a noticeable drop in performance by going to the i5-520M or 540M.

 

Well it seems that other gaming notebooks with the LEDs have even worse battery life so I'm kinda stuck here. Just trying to get the best (by comparison) battery life out of a gaming laptop.

I've been looking for switchable graphics laptops too but it seems the models that offer switchable graphics right now are the ones with graphics cards that aren't top of the line anyways.

 

1. Screen size, which are indirectly related to screen resolution.
2. 620M is equal or faster than 720QM with lower power

Go with a good SSD drive like the Intel X25-M, that'll help your battery degradation level down the road, and consumes less power in idle to medium usage models.

In my opinion, the optimization done by the manufacturer is just as important as the technology itself. A sub-par low power LCD technology like LED might not be better than high quality previous gen backlighting technologies.

 

1. Screen size
2. Get a bigger battery and get i7 quad... it would help much more in muti-threaded apps and RTS games... and u don't have to worry about power-consumption as the cores can shut down when not being used when surfing web.

 

Would the extra cores shut off on their own or would that have to be user controlled?

 

If you're worried about power stick with the i5-520M or 540M, they will be good enough in terms of performance and will give a lot better battery life than the i7 quad core. The cores will shut off automatically.

 

QFT. The 540M is a very fast mobile CPU, and from what I'm reading from other Envy owners it runs a lot cooler than any quad core out there. I love mine.

 

The only reason laptops with LED screens have 'worse battery life' is that the mfgrs use the LED screen as an excuse to use a smaller battery.

Statements like 'worse battery life' without supporting information such as power drain and battery capacity are worthless.

 

unused cores should shut off on their own, same for unused cache.

 

Looks like 720QM might fit the bill. Should hold up for 2-3 years? Not kill the battery when I'm unplugged and have the extra cores when i need it

 

The 720QM offers no tangible benefits over 620M, 540M, or even the 520M...

 

You should consider the M11x even though it sounds like you want a bigger laptop. You will always have to make a compromise somewhere. Either a 15'' with a spare battery or one of the very few models that use switchable graphics i.e M11x.

 

well I was considering the m15x for a while but the lack of numpad (i'm an accounting student), weak gpu (by comparison), and was way too flasy for business

 

You can purchase a USB numpad.

Also, you could write up the FAQ in the What notebook should I buy forum. You might not get the perfect answer, but at least you might get some ideas for other models.

 

I've gone through that forum and the main answers I got were

ASUS G73JH - terrible battery life
HP Envy - overheating issues and no optical drive
Thinkpad - graphics is on the weak end/ have had a lot of friends buy lenovos that ended up faulty
Sagers - battery life is horrendous
MSI GE600 - graphics is decent but I want it to last more than a year
Sony Vaios - Z is too small a screen for me, F series has subpar graphics and no numpad
MSI GX640/GX740 - seems to fit my bill so im hoping to squeeze battery life out of one the 2

 

your best bet is Asus G73... the MSI also seems to have bad battery life... the asus actually has a allright battery life... the reviewer here was able to squeeze out 1h 48mins which is quite good for these desktop replacement notebooks... u might be able to squeeze out more using a 12 cell battery if available.

 

I get 5+ hours from my year old HP G70 and an after-market ebay 12 cell battery. Conventional CCFL backlight behind the 1440x900x32bit 17.3" screen. Only a T4200 cpu (and 4 Gb ram) but it's good enough to run a pair of Server2008 or RHEL virtual machines alongside Win7Pro/64. The only time I'm NOT running virtual machines is when I'm not 'working'. Otherwise I generally have Photoshop CS4 and Lightroom running. Still banging away at the cpu, ram and hard drive.

I *think* that I'd get better battery life with a 'better' cpu, one that has real VT support but I'm not sure. In my mind it's not worth the $150- it would take to find out.

My bro in law just picked up an HP G71 (1600x900x32bit) with the LED backlight. His brand-new 6 cell battery gives him 5 hours runtime. His usage pattern is somewhat 'lighter' than mine as he doesn't run any virtual machines at all nor does he run Photoshop.