Surface Pro 3 Core i3, i5, and i7 will all have equivalent battery life

If you’re still considering picking up a Surface Pro 3, but the processor choice has you confused, you can cross one concern off of your list: battery life. It was only a few days ago that we learned exactly which Intel Core i3 and i7 processors would come with the device, greatly impacting everything from clock speed to graphics.

The rule of thumb in computing is that the faster and more powerful the processor is, the more battery it will consume. But not so fast.

Intel’s Core processors have a wide range of speeds and options for OEMs who chose them. While the Core i7 used in the Surface Pro 3 is not the latest version, it’s the one most ideal for power vs. battery life vs. the need for cooling. Indeed, the Core i7 used can Turbo boost up to 3.3 GHz while the Core i5 version only goes to 2.9 GHz. Interestingly though, the Core i7 has a lower base speed of 1.7 GHz versus 1.9 GHz for the Core i5 edition.

Surface Pro 3 battery

Due to some smart work by Intel and Microsoft in selection of the processors, they all should get around that 9 hour benchmark that Microsoft claims for ideal battery life (most reviews have been putting it 8.5 hours, which is pretty close). Surface team guru Panos Panay just answered this question on battery life in the ongoing Reddit AMA:

“The battery performance is the same across the i3, i5, and i7. The i7 will see benchmark scores appx. 15-20% better than the SP3 i5.”

So there you have it. The Core i7 won’t sacrifice battery life, but you will get a 15-20% increase in performance. Combined with the better video graphics (HD4400 vs. HD5000), the Surface Pro 3 with Core i7 should be quite the performer.

Is that extra horsepower worth the extra $250 between the two versions ($1299 vs. $1549 for the 8GB versions)? That’s up to you, but at least that precious battery life won’t be an issue.

Source: Reddit AMA

Daniel Rubino

Daniel Rubino is the Editor-in-chief of Windows Central, head reviewer, podcast co-host, and analyst. He has been covering Microsoft since 2007 when this site was called WMExperts (and later Windows Phone Central). His interests include Windows, laptops, next-gen computing, and for some reason, watches. Before all this tech stuff, he worked on a Ph.D. in linguistics, watched people sleep (for medical purposes!), and ran the projectors at movie theaters because it was fun.

  • Whew! Not that I have a need for the i7 version, just nice to know battery life is equal.
  • I totally want to rock the i7. This sucker needs to be awesome so I can carry it to my grave in case nobody ever does a model this good again.
  • I doubt they'll be totally equal. You can't run a high bin i5 @ 2.9 and an i7 @ 3.3 and get the same battery life. I imagine they will have similar battery life on web browsing and such, but when you run them full throttle the i7 will die first. The same thing happened to the MacBook air after all, and that thing has no battery life rival even after a year.
  • Yeah there is no way it's going to turn out to be equal in real life usage tests.  For how they measure in "web browsing" or whatever low power state functions I can see it being potentially equal. This is a PR gaff from the start.  He should have clarified. Regardless, Macs with similar specs are still going to trounce the battery life.  It seems that the weak link in battery life is either the size of battery involved or the OS, maybe both.
  • it takes less time to run the same job for the faster cpu. when you feed both of them the same full throttle jobs the i7 will back to rest first.
  • You need to re-read the article again and everyone else that missed this; He said the i7 has a lower clock speed than the i5 so YES they can actually have the same battery life. Reading people, they probably taught you this in school.
  • TxDrum is right, using an i7 and an i5 on Ie for example will probably have similar battery life seeing as the i7 won't be running full throttle, however run a stress test on both and leave the 2 on until battery goes, then you will have an accurate representation of battery comparison.
  • I would expect the i3 to give me gobs more battery life, weird.
  • Perhaps they are putting a smaller batter in those to keep costs down?
  • The simple answer is the more powerful processors work faster than idle back, but I still find it hard to believe the i7 and i5 have similar power consumption under higher continuos loads...
  • Allegedly. No OEMs battery claims have ever proved to be accurate so bucket of salt needed with this one.
  • They've obviously tested them and so far, the SP3 Core i5 does get close to the 9 hours advertised. I mean, if the Core i7 comes out with 5 hours battery life, I'm not sure how Panos can backtrack on this claim.
  • I wonder if anyone's going to test the 1-year standby time lol
  • "Most reviews have been putting battery life at 8.5hours...." Do keep up ;)
  • maybe need a little tweak in power configuration to get 9 hours battery life.
  • Apple isn't lying afaik... All other OEMs I've tried so far are.
  • Daniel, if possible could you run a stress test on the 2 versions and see how long both last?
  • So how long is it? Like 9 hours long? Is that on full bright or or half way bright? Is that web browsing or media consumption? I feel like 9 hours is not enough for someone who's out everyday like me from. 7 to 8pm which is 12-13 hrs. I work/class mostly everyday.
  • 9 hours video or web. Yes, brightness at 50%.
    "I feel like 9 hours is not enough for someone who's out everyday like me from. 7 to 8pm which is 12-13 hrs."
    I find it difficult to believe you're working on a computer for 12-13 hours a day straight with no outlet near you. If so, my condolences ;) I use a Core i7 15 inch QHD laptop with dedicated video, 16 GB of RAM and it "only" gets around 7 hours, but that's enough for me to live blog, render video, do photos, run Lightroom and cover an all day event with battery to spare. But hey, if you know you need 12-13 hours, then this is not your device.
  • 'My condolences'...
    :) Some people just like to find issue when really there is none. 9 hours is beyond most peoples working day. & I'm sure the Surface team designed a charger to go with the SP3 that delivers a good charge from just a short charging session.
  • 90 minutes of charging reportedly gives 70+% battery back. And yes, I don't think regular students, artists, programmers, professionals are using 7-9 hours of battery mobile every day without an outlet. I'm sure there are those who do need that, but obviously they need a different device.
  • I would like to see if it could be powered by a battery pack.  I initially suspect not because of the probable power draw from the CPU.  Perhaps the internal battery could however at least be recharged by one without the product being used.
  • This is why I remain content with my Asus T100. Recharging via micro USB is a great thing. I can recharge it whilst I'm driving via the little USB lighter socket adapter. & I can recharge it whilst I'm out hiking and whatever else using an Anker battery pack. For someone that craves being out in the wilderness, but who still needs access to various productivity tools for business, the T100 is a gem.
  • Yep I agree the T-100 is a great price for proformance... I have left the little guy fully charged and completly off for over a month and open it up and it still reads full. I would like to check out the SP 3 but the Asus does it all for me now...  it's a little heavy with the Keyboard attached but the USB 3 makes it much more functional with a USB 3 hub. $350.00 vs $1500.00  
  • actually rjmlive, it's basic electronics, YES of coarse you can add more power with a battery pack. That's like saying I wonder if I can eat one more taco, yes you can. there's 2 ways to do it. something already packaged with a barrell connector and the voltage and wattage required by the laptop or make your own. use a sealed lead acid or AGM battery, charge it with a battery tender designed for the low amp hour battery you selected or equivalent charger. next simply connect a 12 accessory / cig lighter port to it, you can buy it at walmart for $5. next buy a DC (direct current, not AC current)  powr+ charger on amazon rated at the same wattage or higher required by the laptop. to get wattage multiply amps required by the voltage. again always get a larger charger than needed example your laptop requires 15 watts, get 20 or 30 or 40 watts or more. it means the charger wont heat up as much and some chargers do not even put out what they are rated for. lastly stick the battery, charger and etc into a lunch box or whatever, voila, power pack for you. add usb and you can charge your phone. u can even add a mini amp for $25 and put speakers in the box, voila instant portable mp3 sounds.again this is basic electronics, no degree required.
  • My criteria for any of my mobile devices is if I can fly NY to CA or NY to Europe and not have to plug in my device while trapped in a flying tin can.  8.5 or 9hrs are all good for me.
  • okay so i was a bit exagerating on that.  Its just that when my battery is half way full (50-60%) at the end of the night, do I leave it as is or plug it while im asleep?  What scares me is that if i leave it charging overnight, it might overcharge and fuck up the battery.  And if I dont plug it, by the time I wake up in the morning before heading out-- it might already be down to 10-20%.  This is a common issue for me and my phone.  I am afraid of leaving it overnight charging so I let it sit.  Sometimes I try to wake up 5am and plug it then.  That why I dont have to worry about overcharging the batt. LOL  I'm still getting the tablet.  I just need a new habit of charging it.  #firstWorldProblems
  • you can charge it over night, your laptop will not let it overcharge, ocne its full it will stop accepting the charge, what your referring to is when you leave a laptop plugged in all the time and play games on it constantly, creating the trickle charge effect (laptop keeps accepting the charge for a little bit once it drops a certain trheshold and then cuts it off again, THAT is dangerous, charging your laptop overnight is not, hope that clears it up and makes ya feel a bit more confident about charging!
  • There's no need to be concerned charging any modern device overnight. The largest majority of the horror stories you hear of devices exploding or catching fire are from users not using approved chargers. Different devices need different amperage and volts. Some USB wall chargers for example are designed to "fast charge" devices by delivering high amperage. If the device is compatible with that, no problems, and some devices such as the iPad require it. But, if your device doesn't support high amps then you've got problems. As long as you use the provided Surface charger or a replacement from Microsoft, you'll never have any problems.
  • Which is the laptop u use??
    I have hp 15 j101ex 16 gb ram i7 2.2 4 gb dedicated graphics ... 4 hr is the maximim if i browsw, use photohshop and dreamweaver..
  • it's enough if you put it in sleeping mode when you are having lunch or in the bathroom..
  • Lol that's one of the few things they answered. Joe's AMA sounded much better and transparant than this AMA.
  • Agreed. +920
  • And Joe's AMA was BS as well... just marketing gimmiks to have them do AMAs
  • Can i play moba games on the i3 processor?
  • Otro mas...
  • I guess if the tweak the power options in windows & lockout changes using group policy registry settings & a severely gimped video driver they could keep it that way
  • Great Consideration from Microsoft!
  • Anybody want to buy me one? I'll pay in two installments :)
  • Sure! Meet me in a dark alley and give me your money. :)
  • Great! Which dark alley? :)
  • gay avenue in east st. louis, il.
  • Oh dear.
  • Does the actual performance come from Turbo Boost? A bit confused.
  • Maybe now is the time to go hd5000 assuming Intel is going to make it more mainstream over the next 18 months.
  • HD 5000 Graphics will be in the i7 according to the AMA
  • I'm aware, what I'm curious is if Broadwell (coming later in 2014)  and Intel's followup chip .. does hd5000 move down to i5 and even i3 mobile processors.  I bet it will.
  • Super cool for people planning on doing hardcore graphics work and stuff. I have a powerful desktop so I'll defer more performance intensive work for it. I think the i5 256/8 is a great option.
  • What wizardry is this? The power has to come from somewhere...
  • they forged these laptops from the fires of Mordor, also the i7 runs at .2 lower clock speed than the i5, whichever explanation you like best
  • So something else that is coming form the AMA,  sounds like the Power Connector is also a Thunderbolt port  
  • Are you sure?
  • It is not surprising if the cpus have the same TDP
  • I just want to know what kind of realistic limitations I can possibly expect for using the i3 version in terms of not being a "power user".. I'll probably use this tablet in a similar fashion as I use my current Surface RT, which is mainly for the Modern apps from the store, MS Office, and the option to use a few legacy apps if there's a need..
  • Same here. I want to see just how the i3 model will be able to perform. For  me it's either the i3 or i5 model. I have no need for that much power (i7).
  • over powerfull tablet for you! I do the sam
  • Does the keyboard act as a battery also
  • Whyt don't you add the disclaimer that this is a paid advertisment for Microsoft? Do you not see how incredibly assinine this sounds?  It is in realm of Ford being fined for claiming higher gas mileage actually achievable. Yes, they will say it is equvalent because that is waht they need to say. Intel also stopped one step short of claiming 4th generation CPUs would allow double-digit battery life and the current generation Atom CPUs wold take performance and battery life stunning levels.  How did those work out for every one?  Improvement, yes - believable claims, no. if you don't understand how this stuff works and you are going to shill juat be honest about it. 
  • Moan, moan, moan ;).
    Asus T100 here. Surprisingly powerful, nearly 10 hours of battery life, recharges via micro USB and weighs a kg with the keyboard dock.
    Intel delivered.
  • Intel definitely delivered. I always tell my gf that my Dell Venue 8 pro has godlike battery life. Its also a powerful little gadget. I bought a Miracast receiver to hook up my DV8 to my TV. I then hooked up a mouse and keyboard through an OTG cable and im now using my tablet as a full Windows 8 PC and I haven't had a hitch yet. I don't run extremely powerful software but for what I do run there is 0 slowdown.
  • My T100 has morphed into my desktop replacement. I use the keyboard all the time, and actually find it very usable with tactile keys that give good feedback. I also do web design, listen to music, have multiple tabs open....and do video editing on occassion (1080p vids from my 1020). I even did some charity pamphlet/business card designs today with MS Word 2013. It's a surpisingly robust little design editor :). Not bad for a free bit of software! & certainly vastly better than OpenOffice (which I can't ever imagine going back to) It does stutter when doing the 1080p stuff - and sometimes stutters when I've overrun the 2GB's of memory. But by and large, it is one of the quickest and most pleasant computers I've ever used. Cracking bit of kit - and a v.good advert for Microsoft's vision. One thing I particularly like --- OneDrive displays all of my cloud files even if I haven't downloaded them to my computer. Makes the whole cloud thing very seamless...
  • Not waiting until Sept for an i7.
  • ..but not equal gpu performance ... Can we get HD5000 on all CPUs plz, those Flash websites need more GPU cores.
  • super power tablet for you! I do the same things on my old Lenovo Lynx tablet with a poor Intel Atom. i3 is just a lot of power, will be fast!!!!!
  • No LTE... not for me and many others but this is one of,the best hybrid laptop I've seen so far. Too bad Microsoft forgot to add this feature.
  • why? You can buy any LTE adapter from any vendor on any network you like.
  • Absolutely right. Built-in LTE capability comes with a price so I'd rather buy a separate LTE adapter.
  • well some basic logic here, if it is faster then it does things in less time therefor using the same battery as doing it slower lasting more, but thats for "normal" usage, if you  use both of them at full power it is obvious which one will die first
  • that's not logic at all, in fact it's illogical. for even if that was true unless they both rest at the same power consumption, which should not be the case...anyways my point is if you re-read the article, the i7 runs at a lower clock speed than the i5 which is what is negating the battery life differences between then. Nice try trying to trick us an all though, was a good effort
  • let me explain again, if it takes you 20 minutes to compress a file using winrar with the i5, and doing it on the i7 takes 10 minutes, considering the i7 requires twice the energy, there would not be a difference since the time reduction compesates for the extra power needs, of course it is not so simply as you pointed out on standby mode it does that little trick, but what if i told you an i7 running at 1ghz is as fast as an i5 at 2ghz? experts are still debating whether or not "GHz" is a good way to measure CPU performance
  • i7 ftw
  • Honestly, if you are just going to be running Office and surfing the web, the i3 will be MORE than enough.  Too bad it doesn't come out until end of August.
  • Also people just so you know the more powerful processors are being CPU throttled, meaning they are throttling back their performance under heavy load by decreasing the clock speed when needed, i.e. when heat or demand increases., that with the already lower clock differences between each CPU is your technical explanation of how microsoft is able to provide the same battery life between each of these, no black magic here, sorry to burst everyone's bubble but so much misinformation spreading on here someone needs to clarify it.