Hard Drive Performance Crossover Point? [size+RPM vs capacity utilization percentage]

[strathglass]

Anyone know data to support a decision between two hard drives,
one with more capacity but lower RPM?

I want to know at what capacity the smaller, higher RPM drive might yield slower overall performance than the larger lower RPM drive, due to the smaller drive being much closer to its capacity (and hence having more data on the outer, slower part of the disk).

Specifically, for my Aperture library for my new Macbook Pro I'm considering:
750GB 7200 RPM drive
vs
1.5TB 5400 RPM drive

I will have about 600GB of data initially to put on the drive.
Given this is close to maxing out the 750GB drive capacity, I thought this might provide overall slower performance than the 1.5TB 5400 RPM drive, but I can't find any specific data to guide me.

I'd take the smaller drive if I felt it would perform noticeably better despite being near capacity and not having as much expansion room as the 1.5TB drive.

But if the performance difference would be small or even slower than the larger drive with the lower RPMs given how much data I will have on it, I'd obviously take the larger drive!

Hoping someone out there can offer some facts to support a decision!

Regards,
Colin

 

[thundersteele]

I'd go with the bigger drive in this situation.

Concerning your question, I remember someone saying that larger drives of the same design and rpm have higher data rates, due to the data being packed tighter. I'm not sure whether this is an accurate statement.

How are you planning to connect to your MBP? If it is firewire or USB 2.0, you don't have to worry about the disc speed, since the interface will be the limiting factor. Other than that, I would try to find actual benchmarks for the discs you are considering, instead of looking for a general XX is faster rule.

 

[strathglass]

I'd go with the bigger drive in this situation.

Concerning your question, I remember someone saying that larger drives of the same design and rpm have higher data rates, due to the data being packed tighter. I'm not sure whether this is an accurate statement.

How are you planning to connect to your MBP? If it is firewire or USB 2.0, you don't have to worry about the disc speed, since the interface will be the limiting factor. Other than that, I would try to find actual benchmarks for the discs you are considering, instead of looking for a general XX is faster rule.

Thanks for the quick response.
This is a firewire 800 connection: if that is the limiting factor then it becomes a no brainer. I didn't realize though that this would be the case. But I just googled this and found information that supports what you say.

So 1.5TB it is!
Thanks again.
-Colin