Do 7200rpm hard drives decrease battery life?

Hi W,

wesdog13 wrote:

I am using a (2010) macbook pro 13in and I upgraded my hardrive to a Hitachi 500gb 7200 rpm drive. Do 7200 rpm drives decrease battery life?

If (big if) all other things were equal, yes, a 7200 draws more power than a 5400. But there are so many variables that that's actually a very complicated question. It really depends on the two drives you'd be comparing.

wesdog13 wrote:

Well, the reason I'm asking is because as soon as I installed it i have taken a 1-2 hr battery life loss. Im just trying to narrow down the problem.

No other changes?

Check to see if Spotlight is indexing. Open Activity Monitor and see if any processes are using more than they should. Repair Permissions. Verify Disk. Is your usage very consistent so you're comparing apples to apples (old and new HD)? You can also check in Console.

The difference in like models is less than 1 watt, here's a comparison for you

As I said in your other post, a drop in battery life of approximately 50% did not come from changing the hard drive.

Csound1 wrote:

The difference in like models is less than 1 watt, here's a comparison for you

As I said in your other post, a drop in battery life of approximately 50% did not come from changing the hard drive.

That's a good find, but even that does not tell the whole story. If the areal density and/or number of heads and/or optimization and/or etc. is such that the one with the higher power draw performs reads/writes/transfers more efficiently and/or can cache more data, then that one, the one that draws more power, is actually going to save power while doing its thing in the computer.

You're quite correct, the question is as you stated, very complex. This does not change that the power drawn as a percentage of total power drawn by the machine is quite small, not enough to cause a significant alteration to battery life.

Csound1 wrote:

You quite correct, the question is as you stated, very complex. This does not change that the power drawn as a percentage of total power drawn by the machine is quite small, not enough to cause a significant alteration to battery life.

True dat. 😉

wesdog13 wrote:

Just a suggestion...I am using firevault...would that cause any alteration to battery life? I am constantly opening files/moving them around/creating them (film).

But if that's the same as on the old HD, that's not a variable.

If you installed Lion at the same time you upgraded the HD, and/or started using FileVault2 (I'm not running Lion, so I don't know if you even have a choice), that's a huge difference.

wesdog13 wrote:

I installed Lion on the new HD as soon as I installed the hardware. I burned Lion to a flash drive and booted it up/reformatted/etc. THEN I started using Filevault 2.

That's additional processor time as well as the disk load, certainly won't help the battery discharge rate, it's very hard to be specific here, all you can do is try, PITA though it may be. Wish I had more.

wesdog13 wrote:

I installed Lion on the new HD as soon as I installed the hardware. I burned Lion to a flash drive and booted it up/reformatted/etc. THEN I started using Filevault 2.

I think it's safe to say the issue is Lion related. What or how, I cannot say, but if you do a search here for Lion and battery, you'll find plenty.

You apparently missed the following post. I recommend reading it and trying the troubleshooting:

No other changes?

Check to see if Spotlight is indexing. Open Activity Monitor and see if any processes are using more than they should. Repair Permissions. Verify Disk. Is your usage very consistent so you're comparing apples to apples (old and new HD)? You can also check in Console.