I have a current MacBook Pro 15" i7 2.2Ghz with a 500GB 7200RPM (default) hard drive.

I am thinking of replacing both the current hard drive and the superdrive with two Seagate Momentus Hybrid 500 GB drives and placing them in RAID0 for optimal performance.

Now, I don't think performance will be a problem, but how about battery life? Are there any examples of users who already have done similar things and noticed the effect on battery life?

  • 1
    @cksum RAID0 (a.k.a. Striping) is typically done for performance, not redundancy (since it provides none).
    – Dan J
    Oct 17, 2011 at 18:51
  • Here is an article that may help you see just how much impact an HD has on a system in terms of power consumption: cl.ly/1h0y0g3V1r2n1m0n1V2g
    – user10355
    Oct 18, 2011 at 2:45

3 Answers 3


Having a second hard drive will certainly decrease battery life by a noticeable amount. Behind the CPU and LCD, the hard drive is the largest drain on battery.

A word of caution: RAID 0 is almost never a good idea, unless you'll be doing backups constantly and don't mind being totally down if a drive fails. You'll get better performance from an SSD and you'll be able to keep your optical drive.

  • Or, if you need the space you can add an SSD as your boot and move your existing HD to the optical bay.
    – cftarnas
    Aug 25, 2011 at 6:29
  • Do you have a source for your answer? This chart shows that hard drives are at the bottom of the power consumption ladder (comparable with RAM): pcpower.com/technology/power_usage
    – user10355
    Sep 17, 2011 at 16:35
  • @cksum considering that an optical drive is almost never in use and a 2nd hard drive in R0 by definition would always be in use, it's kind of obvious.
    – MDMarra
    Sep 17, 2011 at 21:16
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    @MarkM +1 for caution about RAID 0, also known as "Scary RAID".
    – Cajunluke
    Sep 17, 2011 at 21:56
  • 3
    @PhilipRegan other SE sites are very concerned about the factual accuracy of their data. If a user on SF, for example, posts something incorrect, other users feel obligated to point out the error as a curtosey to future visitors. I'm sorry if you thought that I was out of line, but someone posting out-of-whack desktop power consumption numbers from 4 years ago in a topic about a brand new notebook is just plain wrong. I know I have low rep here but I'm a 10k user on two of the original trilogy sites. By deleting my answer that rebutted bad* data, you did a disservice to the community.
    – MDMarra
    Oct 17, 2011 at 21:41

Go with an SSD. The lack of moving parts will increase battery life.

On my previous (late 2011) non-Retina MBP, I replaced the optical drive with a 512GB SSD, (The optical drive is basically useless 90% of the time - may as well use the space for SOMETHING.), and moved the operating system installations (OSX and Win7) to the SSD. This significantly improved battery life as well as overall performance.

If you don't want to pony up the cash for two large SSDs, put one SSD in along with a higher RPM spin drive.

Also, check out the Corsair 16GB RAM upgrade available from Newegg, among other places. Takes about 10 minutes to install, doesn't void your warranty, and also really helps overall performance.


i wonder how well a hybrid will work in a raid0. could there be some logic that would make the ssd portion of this hybrid useless when used as a raw raid0 drive?

i'm not sure about their logic of caching from spinning drive to the ssd portion. but if it's by file name or structure, the raid-0'ness of it might defeat that.

just a thought

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