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i5 vs i7... battery life?

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far4477

macrumors member
Original poster
Apr 20, 2011
30
0
Hello everyone. I am still undecided whether I should get the i5 or i7 13 inch MBP.
For my needs the i5 is probably enough (photoshop, some cubase which was running just fine on my 2009 MBP, so the i5 is already an upgrade from that...), but my main need is portability. And battery life is extremely important in terms of portability. Now, is there a big difference in battery life between the i5 and i7 versions? Because if there is, i'd take more battery life over the probably unnoticeable difference in power between the 2 processors.
 
Makes sense. I remember reading a Tom's Hardware review on SSD battery life that was criticized its use of benchmarks instead of a browser reloading check. Since there was no idle time as there would be in real life, the benchmark made the SSD work harder than the HDD so it consumed more electricity than it would if you were using it to process a throttled amount of information, such as a proposed reloading webpages at regular 5s intervals. Lost the article criticizing Tom's tests but you might see some of the dissent in the comments and I'll edit in those results later if I find them.

With that information in mind, I'd only worry about a faster processer killing my battery if I was using my MBP to multitask with low processor work like playing music or doing paperwork. I mean in theory, running Photoshop at higher speeds would drain the battery quicker, and give me less overall time to finish my report right? That being said, the difference in performance probably will be notable if the battery life does get reduced by any considerable amount.
 
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On Idle or close to idle the i7 needs no more power than the i5. They clock down to the same low clocks and voltages. Only at full speed there is a difference and if you want to get anywhere near the proclaimed 7h you need to spend very little time at full speed.
Also there is the idea of run to idle, which says that the faster CPU often saves battery because it is longer/sooner running idle and the difference between idle and load is huge compared to the difference between load on a slow and fast CPU.

Base your decision on how much you value the increase in speed vs. the increase in price. Battery life will be not much different.
 
I think in the end i'll opt for the i7. I want to keep this laptop for a while and really I am someone who uses photo editing / music software and the 300$ wont change my life, and if the battery life is the same then i think i'll just get the most powerful one
 
far4477 said:
Hello everyone. I am still undecided whether I should get the i5 or i7 13 inch MBP.
For my needs the i5 is probably enough (photoshop, some cubase which was running just fine on my 2009 MBP, so the i5 is already an upgrade from that...), but my main need is portability. And battery life is extremely important in terms of portability. Now, is there a big difference in battery life between the i5 and i7 versions? Because if there is, i'd take more battery life over the probably unnoticeable difference in power between the 2 processors.
Click to expand...

There'd be some difference as the 17" screen is going to be larger - in terms of power/performance considerations, the high-end 15" is the best choice IMHO.

If you keep wifi and bluetooth off, that'll help as well. Ditto for keeping brightness down.
 
far4477 said:
I think in the end i'll opt for the i7. I want to keep this laptop for a while and really I am someone who uses photo editing / music software and the 300$ wont change my life, and if the battery life is the same then i think i'll just get the most powerful one
Click to expand...

GREAT choice, actually! I was happy with my mid-2009 17", but the 2011 models are far far ahead in performance. (dual-core with 2 threads vs quad-core with 8-threads is a no-brainer given what I need it to do.)

The 15" will still have better battery life, but for long-term use nothing is going to beat the quad i7 model. (I apologize for not seeing your last response before my previous post...)
 
IIRC the power management that is used now will throttle both the 7 and 5 back, and battery difference seems to be nominal, (as said) compared to specific user tasks.
 
I dont know if this helps but i use my 13inch i5 base model for loading
aperture 3 and footage taken on my Contour 1080HD head cam
I put all my stuff onto an Lacie 1TB hard drive.

All i do is load everything on location and edit back at base or at home on a external TV/Monitor.
Just save your money and buy the base model, thats what i did and bought the above items with the money saved.
 
do SSD help battery power?

im pretty sure i have read somewhere that they do.

so for the purpose of this post im going to assume it saves a little power.

Id go i5 with a SSD. this way you can save power and still have a really fast machine (for what you're doing importing and exporting the SSD would help a lot).

i5 ssd > i7 hdd
 
Like the processor, it depends on how hard its being worked. In theory a S.S.D. being worked to the hilt will die much, much faster as detailed in the Tom's Hardware article I linked above. (It'll get more tons more work done in the meantime though so it's a somewhat moot point.)

However assuming normal usage, with the drive being allowed to idle as the HDD is which is a much fairer comparison since the drive is accessed at an on demand basis, you might see an estimated extra 10 minutes because there's nothing to motorize. Just raw data access.
 
Why are some of you going on about 15" and 17" MBP's? The OP is asking about the difference between the i5/i7 in the MBP13.

OP: Based on your criteria... I'd skip the i7 upgrade. It's a lousy value for what you get. Also, search the forums regarding all the heat issues concerning the MBP13. That i7 certainly isn't going to help with this.

Use the $300 for an external monitor to edit your photos or apply it towards an SSD (as already mentioned).
 
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