[iohead]

Here's an annotated summary of "on-paper" differences between a few popular drives for the PowerBooks:

http://www.kernelthread.com/mac/pb17/diskdrives.html

-A

[michael_on_mac]

Very nice and thoughtful comparison.

I am in a little doubt that the acoustics numbers are right:
figures that low cannot be decibels (3.5 dB would be absolutely inaudible) but something different, maybe not on a logarithmic scale.

Anyway, I could fully agree with his conclusions.

Comments?

Best, Michael.

[iohead]

Originally posted by michael_on_mac:
Very nice and thoughtful comparison.

I am in a little doubt that the acoustics numbers are right:
figures that low cannot be decibels (3.5 dB would be absolutely inaudible) but something different, maybe not on a logarithmic scale.

Anyway, I could fully agree with his conclusions.

Comments?

Best, Michael.

You're right - they are bels, not decibels. I'll correct it

-A

[nagromme]

Thanks!

Two things that strike me are that battery life is unlikely to suffer noticeably, and that the 7200 is a smaller drive! 60 GB. That makes the 80 GB 5400 sound best to me--for a price. I wouldn't touch the 7200 and lose my warranty.

I'm still not sure about the noise (a pin dropping--constantly--could be annoying!) but I'd probably survive. And real-world app comparisons would be nice to hear about, as more users get these.

For the sake of thoroughness, you COULD add:

* Street price of the 7200

* Mention of the voided warranty if you choose the 7200

* Note which of those 4200s is in the 15" and which in the 17"

But what you've got is great--thanks again!

[nagromme]

A little math on those Travelstar max transfer numbers:

5400 is 29% higher than 4200
7200 is 15% higher than 5400

I know that's not real-world, but anyway, BTO'ing the 5400 over the 4200 looks like a bigger leap than choosing the 7200 over the 5400.

[michael_on_mac]

Hi all!

Another thing often not known: The transfer speed (which is not really the most important number for 'normal' use, but anyway) does not only depend on the rpms, but as well on the data density.
This is actually the reason why recent 4200 drives are often faster than older 5400 drives with lower data density.

Therefore I'd like to know the capacity per platter - which are 15 GBs and which 20 GBs - does somebody have this number?

Best,
Michael.

[ctishue21]

I believe the Hitachi and the Fujitsu 4200rpms that Apple uses in the new powerbooks are 2 platters, 40GB each, 2 heads per platter, with an 8MB high speed cache. This is why they perform so well compared to older 5400rpm drives. This is also why I chose to stick with the stock model and not pay extra for BTO and extra tax from my state for the 5400rpm totalling $175. My 17" feels plenty fast. It launches all my applications much faster than the dual 500 G4 it is replacing.

[chabig]

Transfer speed does depend on RPM and data density. But no matter what the density is, the faster drives always have smaller latencies.

Chris

[chabig]

iohead--

Nice comparison. I want to bring one other "mistake" to your attention, if you're willing to correct it.

Regarding battery endurance, you use this formula:

watt-hours / watts = hours

That's not quite right, you should rearrange the terms so...

watts / watt-hours = hours

Chris

[Podolsky]

Thank you for this. I am glad I BTOed the 5400 into my 17". I plan on keeping it for 2 years and going with this modest cost increase to do it under waranty was worth it to me. This way, it is just one thing I don't have worrry that I should have done....

[Mskr]

Originally posted by chabig:
iohead--

Nice comparison. I want to bring one other "mistake" to your attention, if you're willing to correct it.

Regarding battery endurance, you use this formula:

watt-hours / watts = hours

That's not quite right, you should rearrange the terms so...

watts / watt-hours = hours

Chris

Uhhhhhh. No.

Code:
Watt-hours = w * h
Watts used  = w

(w * h)
 ----  = h
   w

So, let's say a battery has a 40 watt-hour rating, and the total draw of the entire system is 8 watts, you'd get 5 hours of use out of that battery.

Using your formula:

Code:
  w
----  = h
w * h

would mean that the you'd get 0.2 hours, or about 12 minutes. Finally, your formula couldn't be right, because in the real formula, the w in the numerator & denominator just cancel each other out to give you:

Code:
h = h

Make sense?

[amazing]

Rob-Art Morgan has tested the various HDs both in the 15" AlBook and in fw400 and fw800 cases. The figures are very interesting (there's a couple places where his graphs aren't proportional, be sure to note the actual figures)

http://www.barefeats.com/hard34.html

The one thing I really noticed was how great the external firewire performance was. Since replacing the HD in the new crop of powerbooks could void the warranty, that's the way I'd go.

I would still get the 5400 internally, because you're not going to be able to replace it down the road. Regardless of Apple's prior experience with the aluminum firebook and lapzilla, this is still a first generation model--and that means getting the extended applecare, because stuff is expensive in the laptops.

[chabig]

I humbly apologize for my own mistake concerning the equation for battery endurance: w-h / w = h

I was completely wrong, it was right before I spoke up, and there is no excuse for my error. Sorry.

Chris