7200 vs 5400 rpm for TM

Stephen.R

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So for a general use spinning rust drive, higher RPM means lower latency, but it used to be the case that 5400rpm drives used higher density platters, and thus could actually give better speed for sustained sequential activity.

My intended use for this specific drive (actually pair of drives, in a software raid1) is dedicated to Time Machine backups.

Has anyone done any research or real world tests with modern (~6-8TB drives)?
 

Stephen.R

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Isn’t the helium just about less friction than “air”? How does that relate to seek time vs platter density for effective data I/O rate for backups?
 

casperes1996

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Jan 26, 2014
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Isn’t the helium just about less friction than “air”? How does that relate to seek time vs platter density for effective data I/O rate for backups?
Yes. And because of that they can keep the head more stable at faster speeds meaning more dense platters become more feasible at higher RPMs. - That's my understanding anyhow
 

vertical smile

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Sep 23, 2014
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higher RPM means lower latency
Higher RPM also means higher throughput too.

The basics of it is that if there are two identical drive in every way, except the RPM of one is 5400 and the other 7200, the 7200 would give you better performance in every way except power consumption.

But, most people are not comparing two identical drives, but drives that have different characteristics.

but it used to be the case that 5400rpm drives used higher density platters, and thus could actually give better speed for sustained sequential activity.
This could be the case.

I can't remember the exact situation, but IIRC, the first 1TB or 2TB 2.5" drive was only 3400 RPMs.

This was kind of a turn off for many people, but the platters were so dense compared to the smaller capacity drives at that time, that the 3400 RPM drive had higher throughput than smaller capacity drives with 5400 RPMs.

So, to answer your question, you have to find a suitable balance between RPM, density, and price to meet the speeds you are looking for at the price you can pay.

But, if this is just for TM, I personally wouldn't worry about speed so much.
 

Stephen.R

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you have to find a suitable balance between RPM, density, and price to meet the speeds you are looking for at the price you can pay.

But, if this is just for TM, I personally wouldn't worry about speed so much.
You're right of course. It's ultimately not really a user-facing service (unless you need to restore a single file of course), it's mostly curiosity.