Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

81Tiger04

macrumors 6502
Original poster
Aug 11, 2009
465
37
SC
I've read where users see a reduction in battery life when going from a 5400 RPM to 7200 RPM HDD. Is this true? How big is the reduction in battery life?
 
There will be a reduction

Hey,

There will be a definite reduction in battery life of the machine. This is down the the faster HDD having a faster, more power consuming motor.

As for how much the reduction will be is hard to say as different HDDs will have different motors which will each have different power needs.

If battery life is a real issue for you I suggest getting an SSD. Yes it will be very pricey for a decent size drive but it will make your machine run way faster than any 7200 RPM HDD and it will also increase your battery life as there are no moving parts.

Hope this helps.
 
I know it's still hard to give a definite number, but let's say we're talking about the Apple-supplied HDD's.
 
Well its still pretty impossible to say. You need to do all the math such as first knowing how apple calculated the battery life based on the existing components then change the value they used for the hard drive power consumption so that it represents the power consumption of the new hard drive.

You also need to take into account factors such as how the type of usage can also effect battery life. For example just sat there browsing the net with firefox won't drain the battery as fast as if you had aperture open editing photos.

There is no exact figure
 
Understandable ... For the sake of getting a number, let's say 80% of my usage is surfing the internet and other small tasks. Are we looking at a reduction of 10%? 20%? More?
 
I'm going to take a logical guess here. Now please if anyone does know a more exact way to figure it out then please correct me.

The 7200 HDD spins 25% faster than a standard 5400 HDD so I would say approx a 25% decease in battery life, but that may not be accurate.
 
I've read where users see a reduction in battery life when going from a 5400 RPM to 7200 RPM HDD. Is this true?
It completely depends on which specific models you're talking about, since not all 7200 rpm drives are the same on power consumption.
There will be a definite reduction in battery life of the machine. This is down the the faster HDD having a faster, more power consuming motor.
That is not always the case. Some 7200 drives consume less power than some 5400 drives. Again, it depends on which specific models you're talking about.
The 7200 HDD spins 25% faster than a standard 5400 HDD so I would say approx a 25% decease in battery life, but that may not be accurate.
That is not accurate at all, as there is not a direct correlation between drive speed and power consumption.
Understandable ... For the sake of getting a number, let's say 80% of my usage is surfing the internet and other small tasks. Are we looking at a reduction of 10%? 20%? More?
In most cases, depending on which models are being compared, I'd guess somewhere between a 5% increase and a 5% decrease in battery life.
 
I know it's still hard to give a definite number, but let's say we're talking about the Apple-supplied HDD's.
Hi,
I had a High Res i7 MBP with a 7200 and I changed it for a normal res with a 5400 disk. Without making any benchmarks, I'd say that the 7200 has around 20-30 mins less battery life.
 
Hi,
I had a High Res i7 MBP with a 7200 and I changed it for a normal res with a 5400 disk. Without making any benchmarks, I'd say that the 7200 has around 20-30 mins less battery life.

I would say that is about right from my experience. When I switched from the original 5400rpm to the 7200.4 seagate I noticed a little difference but found that dimming the screen another notch restored most of the battery time. I would rather have the extra performance than another 30mins of battery life and I can always dim the screen if I need more battery time.
 
Thanks for your help guys.

If the difference is only 20-30 minutes, I consider that to be pretty minimal and worth the upgrade in speed. If the difference gets to be pretty noticeable (ie over an hour), then that's a different story.
 
I've read where users see a reduction in battery life when going from a 5400 RPM to 7200 RPM HDD. Is this true? How big is the reduction in battery life?

I went from 5400 hitachi to 7200 seagate momentus and the battery hit was crippling. I went from being able to travel to London and back from bristol on a single charge to losing power over halfway on the first journey.

Personally the speed isn't worth the hit, but others may disagree.

london - bristol is about a 2hr journey, by the way.
 
how much of an increase in battery life could a stock SSD user expect to get if running the 15" 2.6 i7?

A couple extra minutes? Half hour?
 
FWIW ... I just talked to a CS Rep at Apple and he said the difference in battery life between the 5400 and 7200 are "nominal." He said that the main drain on the battery is from the graphics card, not the HDD. He then went on to explain how power is conserved, etc. Anyway, I thought I'd share ...
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.