Are Intel Core i3 and i5 processors good for battery life in laptops, or should I go for a lower grade processor?

well I would have thought it would only run up the battery faster if she were clocking the cpu for all its worth, ultimately its a laptop though, you don’t need that much power…

have you checked out netbooks like the Aspire Ones and Hp Mini, Samsung etc my gf has one cost about £300–350 and you easily get 7hrs out of the battery…

they run perfect spec for running 7 without any lags, will play some games, ms office no worries, even 720p video on my D250 and that’s not exactly a high spec netbook!

I can’t speak generally, but I recently got a Dell Studio 15 laptop with an i5 processor and the battery life is almost 5 hours. Pretty fabulous. My friend got the same laptop but with an i7 processor and her battery life isn’t nearly as good

@Tobotron She won’t be using it for movies and videos much, and never for games, so power isn’t really what I’m after. I’m mainly concerned with battery life, but I can’t figure out whether the dynamic adjustment of clock speed in the i3, i5 and i7 would allow it to run more efficiently or if it would just create extra heat and keep it closer to the edge. I’m only looking at Toshibas though, because my family has had six so far without any problems, so they are the only brand I would totally trust for reliability.

@Mariah Thanks. Quad cores always seem to drain the battery, so I wouldn’t be too keen on an i7 or an older quad. Five hours is pretty impressive though, so the i5 must be good enough.

There’s always a trade-off between power and battery life, with the lowest powered processors having the longest battery life. If you want really long battery life and can put up with minimal processing speed and graphics, an Atom processor with Ion 2 graphics is your best bet, such as the Asus Eee PC 1215. The D525 Atom processor is rated at only 13 watts (TDP), while even the mobile version of the I3–330M has a rating of 35 watts. Many Core2 Duo processors operate at 65 watts, but some are as low as 10 watts. The very low wattage versions are rarely found in laptops however.

@FireMadeFlesh I just saw this seeing as your only after Toshiba (had a Toshiba very good, only stopped working because it got stolen haha) but here’s Toshiba’s netbook offering, gives just over 8hrs battery life!!

The links to a UK site but you can probably get this for even less in the US
http://tiny.cc/ia7t3

ah ha US supplier http://tiny.cc/yixbs $300

@GeorgeGee and @Tobotron A netbook isn’t really what we are looking for either. My girlfriend doesn’t have perfect vision, so we have decided on 13.3” or 14” laptops because it provides the perfect compromise between screen size and portability. Thanks for the information though.

The battery life on the Core i3 and i5 is rather anemic.

Personally, I went for the now discontinued Toshiba T135 with it’s 1.3GHz Intel Pentium SU4100 dual-core CPU. It’s not much slower than my desktop i3–530 on most real-world tasks despite my desktop’s CPU being benchmarked at three times the power/speed. Granted, that means that my laptop is slower when I am doing stuff like transcoding videos, but that is like saying that the average car driving down the road is slower than a Ferrari with the pedal floored. Unless you are pretty hardcore, it has the power you need.

My T135 was replaced by the T235 which is slightly improved. It’s a four-pound 13.3” laptop with battery life rated at ”up to 8.93 hours”. Of course, we all know that those numbers are advertising fluff that you’ll never reach in real-world use (they turn the backlight down, turn off the wifi, and do all sorts of stuff to pad the numbers), but a hair over six hours of average use with the wifi on is honestly possible. In fact, it’s so posssible that if you get less than 6 hours with a new one, you should complain!

If battery life matters, avoid the AMD CPUs and stick with Intel. On the T235, the Intel model lasts about 50 (fifty!) minutes longer on a charge than the slower AMD Neo K625.

Here is another review of the Intel-powered T235
They say it has slightly above average performance, a battery life of 6:11 under normal use (category average on their test is 5:32), and overall the best in it’s category (value-priced ultraportable).

I forgot to mention; in real-world use, my T135 beats my old Aspire One by a wide margin when it comes to battery life. Not bad for sometime many times faster and more powerful yet not much larger and barely any heavier.

@jerv Deja Vu! Unfortunately I didn’t see your post before we went shopping, but we ordered a Toshiba T230–00L today. The blurb in the link says it has an AMD K125, but when we played with it it had a 1.3GHz dual core, so I think it was the K325. According to the AMD website it is a 12W processor, so I am quite happy with it. It was around AU$400 cheaper than the Intel version, so I didn’t think it was worth the upgrade.

Thanks for your answer anyway!

Wow! The price difference here is closer to $50 direct and ~$30–40 off the store shelf!

The speed gap isn’t tremendous and you’ll still get over five hours, plus the AMD versions have better graphics, so it’s not like you got a bad laptop.

One thing I don’t like about many laptops is the different versions of the same model. I almost wound up with a T135 with the single-core SU2700, which is barely faster than a netbook; good thing I checked the for digits after the model number :p

@jerv The AMD was actually a little faster going by clock speed, 1.3 vs. 1.2GHz. I was quite surprised that the one in the link has a single core almost-netbook-speed processor. Ever since a salesman tried to tell me my Eee 1000H had a dual core Atom I have checked to make sure I’m getting what I think I am. I sometimes learn the hard way.

@FireMadeFlesh By that logic, my old Pentium 4 should be faster than my Core i3–530 since 3.4 GHz is more than 2.93 GHz, but it isn’t. In fact, even my laptop’s 1.3 GHz Pentium SU4100 is faster than that 3.4 GHz P4 and my netbook’s 1.6 GHz Atom N270.

Clockspeeds can only be used accurately when comparing chips within the same family. Even comparing the closely related Core i3 and Core i5 by clockspeed is inaccurate. And when you compare Intel to AMD with clockspeed, that is like comparing apples and orangutans; read a litle about performance ratings and see for yourself. It gets a little murkier when you compare single-cores (like that P4 and the Atom N270) to a multi-core (like the i3–530 and SU4100).

@jerv I said “going by clock speed” because I knew it isn’t the ultimate measure of speed, but I wasn’t sure exactly how little an indicator it is. Thanks for the information.

According to this list the SU4100 beats the K325 by 998 to 761 while the K125 gets a 521.

I use that list quite a bit.